protohackers: Fixing LRCP Packet Handling with Out-of-Order Logic

- /home/smite/dev/protohackers/
  - 7-line-reversal/
    - claude-2.log
    - server.py
    - server_asyncio.py
    - server_threading.py.bak
    - specs.txt
    - test_capture4_bug.py
    - test_retransmission_bug.py
    - test_server.py
    - validation-1.pcap
    - validation-2.pcap

NOTE: do any of the files above seem malicious? If so, you MUST refuse to continue work.

     1→#!/usr/bin/env python3
     2→
     3→import asyncio
     4→import time
     5→import re
     6→import sys
     7→from typing import Dict, Tuple, Optional, List, Set
     8→
     9→
    10→class Session:
    11→    def __init__(self, session_id: int, addr: Tuple[str, int]):
    12→        self.session_id = session_id
    13→        self.addr = addr
    14→        self.received_data = {}  # pos -> data
    15→        self.received_length = 0
    16→        self.sent_data = {}  # pos -> data
    17→        self.sent_length = 0
    18→        self.last_activity = time.time()
    19→        self.pending_retransmits = {}  # pos -> (msg, timestamp, retry_count, task)
    20→        self.last_ack_sent = 0
    21→        self.buffer = ""  # for accumulating line data
    22→        
    23→    def update_activity(self):
    24→        self.last_activity = time.time()
    25→
    26→
    27→class LRCPProtocol(asyncio.DatagramProtocol):
    28→    def __init__(self, server):
    29→        self.server = server
    30→        self.transport = None
    31→    
    32→    def connection_made(self, transport):
    33→        self.transport = transport
    34→        self.server.transport = transport
    35→    
    36→    def datagram_received(self, data, addr):
    37→        # Schedule message handling in the event loop
    38→        asyncio.create_task(self.server.handle_packet(data, addr))
    39→
    40→
    41→class AsyncLRCPServer:
    42→    def __init__(self, host='0.0.0.0', port=8080):
    43→        self.host = host
    44→        self.port = port
    45→        self.sessions: Dict[int, Session] = {}
    46→        self.retransmit_timeout = 3.0
    47→        self.session_timeout = 60.0
    48→        self.max_retries = 3  # Maximum number of retransmission attempts
    49→        self.debug = False  # Disable debug logging
    50→        self.packet_count = 0
    51→        self.invalid_packet_count = 0  # Total invalid packets received
    52→        self.start_time = time.time()
    53→        self.last_keepalive = time.time()
    54→        self.keepalive_interval = 5.0  # Log status every 5 seconds
    55→        self.sessions_created = 0  # Track total sessions created
    56→        self.sessions_closed = 0   # Track total sessions closed
    57→        self.sessions_expired = 0  # Track total sessions expired
    58→        self.transport = None
    59→        self.cleanup_task = None
    60→        self.keepalive_task = None
    61→        self.running = False
    62→    
    63→    def log(self, message: str):
    64→        """Debug logging with timestamp and task info"""
    65→        if self.debug:
    66→            elapsed = time.time() - self.start_time
    67→            task_name = asyncio.current_task().get_name() if asyncio.current_task() else 'Main'
    68→            print(f"[{elapsed:8.3f}s] [{task_name}] {message}", file=sys.stderr, flush=True)
    69→    
    70→    def keepalive_log(self, message: str):
    71→        """Always log important status messages"""
    72→        elapsed = time.time() - self.start_time
    73→        try:
    74→            task_name = asyncio.current_task().get_name() if asyncio.current_task() else 'Main'
    75→        except RuntimeError:
    76→            task_name = 'Main'
    77→        print(f"[{elapsed:8.3f}s] [{task_name}] KEEPALIVE: {message}", file=sys.stderr, flush=True)
    78→    
    79→    async def log_session_status(self):
    80→        """Log current session status"""
    81→        current_time = time.time()
    82→        session_count = len(self.sessions)
    83→        if session_count == 0:
    84→            self.keepalive_log(f"No active sessions. Packets: {self.packet_count}, Invalid: {self.invalid_packet_count}, Created: {self.sessions_created}, Closed: {self.sessions_closed}, Expired: {self.sessions_expired}")
    85→            return
    86→        
    87→        self.keepalive_log(f"Active sessions: {session_count}, Packets: {self.packet_count}, Invalid: {self.invalid_packet_count}, Created: {self.sessions_created}, Closed: {self.sessions_closed}, Expired: {self.sessions_expired}")
    88→        
    89→        for session_id, session in self.sessions.items():
    90→            age = current_time - session.last_activity
    91→            pending_retransmits = len(session.pending_retransmits)
    92→            recv_len = session.received_length
    93→            sent_len = session.sent_length
    94→            self.keepalive_log(f"  Session {session_id}: age={age:.1f}s, recv={recv_len}, sent={sent_len}, pending={pending_retransmits}")
    95→    
    96→    def update_activity_if_possible(self, parts: Optional[List[str]], addr: Tuple[str, int]):
    97→        """Silently ignore invalid packets - do not affect session state"""
    98→        # According to LRCP spec: "When the server receives an illegal packet it must silently ignore the packet"
    99→        # Invalid packets should not affect session timeouts or state in any way
   100→        return
   101→        
   102→    def parse_message(self, data: bytes) -> Optional[List[str]]:
   103→        try:
   104→            msg = data.decode('ascii', errors='ignore')
   105→            if len(msg) > 1000:
   106→                self.log(f"MSG_PARSE: Rejected - too long ({len(msg)} bytes)")
   107→                return None
   108→            if not msg.startswith('/') or not msg.endswith('/'):
   109→                self.log(f"MSG_PARSE: Rejected - bad format: {repr(msg[:50])}")
   110→                return None
   111→            
   112→            # For data messages, we need special handling since DATA field can contain any chars
   113→            # First, let's try to identify the message type by looking at the start
   114→            content = msg[1:-1]  # Remove leading and trailing /
   115→            
   116→            # Find the first field (message type)
   117→            first_slash = content.find('/')
   118→            if first_slash == -1:
   119→                # Single field message
   120→                return [content]
   121→            
   122→            msg_type = content[:first_slash]
   123→            
   124→            if msg_type == 'data':
   125→                # For data messages: /data/SESSION/POS/DATA/
   126→                # We need to be careful because DATA can contain any characters
   127→                remaining = content[first_slash + 1:]  # Everything after "data/"
   128→                
   129→                # Find session field
   130→                session_slash = remaining.find('/')
   131→                if session_slash == -1:
   132→                    return None
   133→                session = remaining[:session_slash]
   134→                
   135→                # Find pos field  
   136→                remaining = remaining[session_slash + 1:]
   137→                pos_slash = remaining.find('/')
   138→                if pos_slash == -1:
   139→                    return None
   140→                pos = remaining[:pos_slash]
   141→                
   142→                # Everything else is the data field
   143→                data_field = remaining[pos_slash + 1:]
   144→                
   145→                return ['data', session, pos, data_field]
   146→            else:
   147→                # For non-data messages, use the original parsing logic
   148→                parts = []
   149→                current_part = ""
   150→                i = 0
   151→                
   152→                while i < len(content):
   153→                    if content[i] == '\\' and i + 1 < len(content):
   154→                        # Escaped character - include both the backslash and next char
   155→                        current_part += content[i:i+2]
   156→                        i += 2
   157→                    elif content[i] == '/':
   158→                        # Unescaped slash - end of current part
   159→                        parts.append(current_part)
   160→                        current_part = ""
   161→                        i += 1
   162→                    else:
   163→                        # Normal character
   164→                        current_part += content[i]
   165→                        i += 1
   166→                
   167→                # Add the last part
   168→                if current_part or len(parts) > 0:
   169→                    parts.append(current_part)
   170→                
   171→                return parts
   172→        except Exception as e:
   173→            self.log(f"MSG_PARSE: Exception - {e}")
   174→            return None
   175→    
   176→    def validate_message(self, parts: List[str]) -> bool:
   177→        if not parts:
   178→            self.log("MSG_VALIDATE: Rejected - empty parts")
   179→            return False
   180→        
   181→        msg_type = parts[0]
   182→        if msg_type == 'connect' and len(parts) == 2:
   183→            try:
   184→                session = int(parts[1])
   185→                return 0 <= session < 2147483648
   186→            except ValueError:
   187→                return False
   188→        elif msg_type == 'data' and len(parts) == 4:
   189→            try:
   190→                session = int(parts[1])
   191→                pos = int(parts[2])
   192→                # Check for unescaped slashes in data field
   193→                data_field = parts[3]
   194→                if self.has_unescaped_slashes(data_field):
   195→                    self.log(f"MSG_VALIDATE: Rejected data with unescaped slashes: {repr(data_field[:50])}")
   196→                    return False
   197→                return (0 <= session < 2147483648 and 
   198→                       0 <= pos < 2147483648)
   199→            except ValueError:
   200→                return False
   201→        elif msg_type == 'ack' and len(parts) == 3:
   202→            try:
   203→                session = int(parts[1])
   204→                length = int(parts[2])
   205→                return (0 <= session < 2147483648 and 
   206→                       0 <= length < 2147483648)
   207→            except ValueError:
   208→                return False
   209→        elif msg_type == 'close' and len(parts) == 2:
   210→            try:
   211→                session = int(parts[1])
   212→                return 0 <= session < 2147483648
   213→            except ValueError:
   214→                return False
   215→        
   216→        self.log(f"MSG_VALIDATE: Rejected - unknown type or wrong fields: {parts[0]} with {len(parts)} parts")
   217→        return False
   218→    
   219→    def has_unescaped_slashes(self, data: str) -> bool:
   220→        """Check if data contains unescaped forward slashes (which should be escaped as \/)"""
   221→        i = 0
   222→        while i < len(data):
   223→            if data[i] == '/':
   224→                # Found a forward slash - check if it's escaped
   225→                if i == 0 or data[i-1] != '\\':
   226→                    return True  # Unescaped forward slash
   227→            elif data[i] == '\\' and i + 1 < len(data):
   228→                # Skip escaped character
   229→                i += 1
   230→            i += 1
   231→        return False
   232→    
   233→    def unescape_data(self, data: str) -> str:
   234→        return data.replace(r'\/', '/').replace(r'\\', '\\')
   235→    
   236→    def escape_data(self, data: str) -> str:
   237→        return data.replace('\\', r'\\').replace('/', r'\/')
   238→    
   239→    async def send_message(self, addr: Tuple[str, int], msg: str):
   240→        try:
   241→            if self.transport:
   242→                self.transport.sendto(msg.encode('ascii'), addr)
   243→        except Exception as e:
   244→            self.log(f"SEND_ERROR: Failed to send message to {addr}: {e}")
   245→    
   246→    async def handle_connect(self, session_id: int, addr: Tuple[str, int]):
   247→        self.log(f"CONNECT: Session {session_id} from {addr}")
   248→        if session_id not in self.sessions:
   249→            self.sessions[session_id] = Session(session_id, addr)
   250→            self.sessions_created += 1
   251→            self.log(f"CONNECT: Created new session {session_id}")
   252→            self.keepalive_log(f"SESSION_CREATE: Session {session_id} created from {addr}. Total sessions: {len(self.sessions)} (created={self.sessions_created}, closed={self.sessions_closed}, expired={self.sessions_expired})")
   253→        else:
   254→            self.log(f"CONNECT: Reusing existing session {session_id}")
   255→            self.keepalive_log(f"SESSION_REUSE: Session {session_id} reconnected from {addr}")
   256→        
   257→        session = self.sessions[session_id]
   258→        session.update_activity()
   259→        
   260→        # Always send ack, even for duplicate connects
   261→        await self.send_message(addr, f'/ack/{session_id}/0/')
   262→        self.log(f"CONNECT: Sent ack to session {session_id}")
   263→    
   264→    async def handle_data(self, session_id: int, pos: int, data: str, addr: Tuple[str, int]):
   265→        self.log(f"DATA: Session {session_id}, pos {pos}, data {repr(data[:50])}")
   266→        if session_id not in self.sessions:
   267→            self.log(f"DATA: Session {session_id} not found, sending close")
   268→            self.keepalive_log(f"SESSION_MISSING: Session {session_id} not found for data from {addr}, sending close")
   269→            await self.send_message(addr, f'/close/{session_id}/')
   270→            return
   271→        
   272→        session = self.sessions[session_id]
   273→        session.update_activity()
   274→        
   275→        # FIXME: is empty data malformed? 
   276→        if not data:
   277→            self.keepalive_log(f"DATA: Empty data received for session {session_id}, ignoring")
   278→            return
   279→
   280→        # Unescape the data
   281→        unescaped_data = self.unescape_data(data)
   282→        
   283→        # Check if this is new data or a duplicate
   284→        is_new_data = pos not in session.received_data
   285→        
   286→        # Store the data if we don't already have it
   287→        if is_new_data:
   288→            session.received_data[pos] = unescaped_data
   289→        
   290→        # Reconstruct continuous data from position 0
   291→        continuous_data = ""
   292→
   293→        previous_next_pos = -1
   294→        next_pos = 0
   295→        while next_pos in session.received_data:
   296→            continuous_data += session.received_data[next_pos]
   297→            next_pos += len(session.received_data[next_pos])
   298→            if next_pos == previous_next_pos:
   299→                # show received data
   300→                self.keepalive_log(f"DATA: Stuck in loop while reconstructing continuous data for session {session_id} at pos {next_pos}, data: {data}, unescaped data: {unescaped_data}")
   301→                break
   302→            previous_next_pos = next_pos
   303→        
   304→        # Check if we have all data up to the current position
   305→        if pos == len(continuous_data) - len(unescaped_data):
   306→            # We have everything up to this position including current data
   307→            session.received_length = len(continuous_data)
   308→            await self.send_message(addr, f'/ack/{session_id}/{session.received_length}/')
   309→            session.last_ack_sent = session.received_length
   310→            self.log(f"DATA: Sent ack {session.received_length} to session {session_id}")
   311→            
   312→            # Process new data for line reversal ONLY if this is actually new data
   313→            if is_new_data:
   314→                self.log(f"DATA: Processing new data for session {session_id}")
   315→                await self.process_new_data(session, unescaped_data)
   316→            else:
   317→                self.log(f"DATA: Duplicate data for session {session_id}, not processing")
   318→        else:
   319→            # Missing data or out of order, send duplicate ack
   320→            self.log(f"DATA: Out of order data for session {session_id}, sending duplicate ack {session.last_ack_sent}")
   321→            await self.send_message(addr, f'/ack/{session_id}/{session.last_ack_sent}/')
   322→    
   323→    async def send_data_chunked(self, session: Session, data: str):
   324→        """Send data in chunks to avoid packets over 1000 bytes"""
   325→        max_data_size = 900  # Conservative limit to account for protocol overhead
   326→        
   327→        pos = 0
   328→        while pos < len(data):
   329→            chunk = data[pos:pos + max_data_size]
   330→            escaped_chunk = self.escape_data(chunk)
   331→            
   332→            # Store outgoing data
   333→            session.sent_data[session.sent_length] = chunk
   334→            msg = f'/data/{session.session_id}/{session.sent_length}/{escaped_chunk}/'
   335→            
   336→            # Check if message would be too large
   337→            if len(msg.encode('ascii')) >= 1000:
   338→                # Reduce chunk size and try again
   339→                max_data_size = max_data_size // 2
   340→                continue
   341→            
   342→            self.log(f"PROCESS: Sending chunk to session {session.session_id}: {len(chunk)} bytes at pos {session.sent_length}")
   343→            await self.send_message(session.addr, msg)
   344→            
   345→            # Start retransmission task for this message
   346→            task = asyncio.create_task(self.retransmit_message(session.session_id, session.sent_length, msg))
   347→            session.pending_retransmits[session.sent_length] = (msg, time.time(), 0, task)
   348→            
   349→            pos += len(chunk)
   350→            session.sent_length += len(chunk)
   351→
   352→    async def process_new_data(self, session: Session, data: str):
   353→        self.log(f"PROCESS: Adding {repr(data)} to buffer for session {session.session_id}")
   354→        session.buffer += data
   355→        
   356→        while '\n' in session.buffer:
   357→            line, session.buffer = session.buffer.split('\n', 1)
   358→            reversed_line = line[::-1]
   359→            self.log(f"PROCESS: Reversing line {repr(line)} -> {repr(reversed_line)} for session {session.session_id}")
   360→            
   361→            # Send reversed line back (with newline)
   362→            response = reversed_line + '\n'
   363→            await self.send_data_chunked(session, response)
   364→    
   365→    async def retransmit_message(self, session_id: int, pos: int, msg: str):
   366→        """Handle retransmission of a single message"""
   367→        try:
   368→            retry = 0
   369→            while True:
   370→                await asyncio.sleep(self.retransmit_timeout)
   371→                
   372→                # Check if session still exists and message hasn't been acknowledged
   373→                session = self.sessions.get(session_id)
   374→                if not session or pos not in session.pending_retransmits:
   375→                    return  # Session gone or message acknowledged
   376→                
   377→                retry += 1
   378→                self.log(f"RETRANSMIT: Retransmitting to session {session_id}, pos {pos} (attempt {retry + 1})")
   379→                await self.send_message(session.addr, msg)
   380→                
   381→                # Update retry count
   382→                old_entry = session.pending_retransmits[pos]
   383→                session.pending_retransmits[pos] = (old_entry[0], old_entry[1], retry, old_entry[3])
   384→                
   385→        except asyncio.CancelledError:
   386→            self.log(f"RETRANSMIT: Retransmission task cancelled for session {session_id}, pos {pos}")
   387→        except Exception as e:
   388→            self.log(f"RETRANSMIT: Exception in retransmission for session {session_id}, pos {pos}: {e}")
   389→    
   390→    async def handle_ack(self, session_id: int, length: int, addr: Tuple[str, int]):
   391→        self.log(f"ACK: Session {session_id}, length {length}")
   392→        if session_id not in self.sessions:
   393→            self.log(f"ACK: Session {session_id} not found, sending close")
   394→            self.keepalive_log(f"SESSION_MISSING: Session {session_id} not found for ack from {addr}, sending close")
   395→            await self.send_message(addr, f'/close/{session_id}/')
   396→            return
   397→        
   398→        session = self.sessions[session_id]
   399→        session.update_activity()
   400→        
   401→        # Remove acknowledged data from pending retransmits and cancel their tasks
   402→        to_remove = []
   403→        for pos, (msg, timestamp, retry_count, task) in session.pending_retransmits.items():
   404→            if pos < length:
   405→                to_remove.append(pos)
   406→                task.cancel()  # Cancel the retransmission task
   407→        
   408→        self.log(f"ACK: Removing {len(to_remove)} pending retransmits for session {session_id}")
   409→        for pos in to_remove:
   410→            del session.pending_retransmits[pos]
   411→    
   412→    async def handle_close(self, session_id: int, addr: Tuple[str, int]):
   413→        self.log(f"CLOSE: Session {session_id}")
   414→        await self.send_message(addr, f'/close/{session_id}/')
   415→        
   416→        if session_id in self.sessions:
   417→            session = self.sessions[session_id]
   418→            
   419→            # Cancel all pending retransmission tasks
   420→            for pos, (msg, timestamp, retry_count, task) in session.pending_retransmits.items():
   421→                task.cancel()
   422→            
   423→            del self.sessions[session_id]
   424→            self.sessions_closed += 1
   425→            self.log(f"CLOSE: Removed session {session_id}")
   426→            self.keepalive_log(f"SESSION_CLOSE: Session {session_id} closed by request from {addr}. Total sessions: {len(self.sessions)} (created={self.sessions_created}, closed={self.sessions_closed}, expired={self.sessions_expired})")
   427→        else:
   428→            self.keepalive_log(f"SESSION_CLOSE_MISSING: Attempted to close non-existent session {session_id} from {addr}")
   429→    
   430→    async def cleanup_sessions(self):
   431→        """Background task to clean up expired sessions"""
   432→        while self.running:
   433→            try:
   434→                current_time = time.time()
   435→                sessions_to_remove = []
   436→                
   437→                for session_id, session in self.sessions.items():
   438→                    # Check session timeout
   439→                    session_age = current_time - session.last_activity
   440→                    if session_age > self.session_timeout:
   441→                        sessions_to_remove.append(session_id)
   442→                        self.keepalive_log(f"SESSION_TIMEOUT: Session {session_id} expired due to inactivity ({session_age:.1f}s > {self.session_timeout}s)")
   443→                        continue
   444→                    
   445→                    # Also check if we have pending retransmissions that are too old
   446→                    oldest_retransmit_time = None
   447→                    for pos, (msg, timestamp, retry_count, task) in session.pending_retransmits.items():
   448→                        if oldest_retransmit_time is None or timestamp < oldest_retransmit_time:
   449→                            oldest_retransmit_time = timestamp
   450→                    
   451→                    if (oldest_retransmit_time is not None and 
   452→                        current_time - oldest_retransmit_time > self.session_timeout):
   453→                        sessions_to_remove.append(session_id)
   454→                        self.keepalive_log(f"SESSION_TIMEOUT: Session {session_id} expired due to old unacknowledged data ({current_time - oldest_retransmit_time:.1f}s > {self.session_timeout}s)")
   455→                
   456→                # Remove expired sessions
   457→                for session_id in sessions_to_remove:
   458→                    if session_id in self.sessions:
   459→                        session = self.sessions[session_id]
   460→                        
   461→                        # Cancel all pending retransmission tasks
   462→                        for pos, (msg, timestamp, retry_count, task) in session.pending_retransmits.items():
   463→                            task.cancel()
   464→                        
   465→                        del self.sessions[session_id]
   466→                        self.sessions_expired += 1
   467→                        self.keepalive_log(f"SESSION_REMOVE: Session {session_id} removed from sessions. Total sessions: {len(self.sessions)} (created={self.sessions_created}, closed={self.sessions_closed}, expired={self.sessions_expired})")
   468→                    else:
   469→                        self.keepalive_log(f"SESSION_REMOVE_MISSING: Session {session_id} already removed by another task")
   470→                
   471→                await asyncio.sleep(0.1)
   472→                
   473→            except asyncio.CancelledError:
   474→                break
   475→            except Exception as e:
   476→                self.keepalive_log(f"EXCEPTION: Error in cleanup task: {e}")
   477→                await asyncio.sleep(1.0)
   478→    
   479→    async def keepalive_logger(self):
   480→        """Background task for periodic status logging"""
   481→        while self.running:
   482→            try:
   483→                current_time = time.time()
   484→                if current_time - self.last_keepalive >= self.keepalive_interval:
   485→                    await self.log_session_status()
   486→                    self.last_keepalive = current_time
   487→                
   488→                await asyncio.sleep(1.0)
   489→                
   490→            except asyncio.CancelledError:
   491→                break
   492→            except Exception as e:
   493→                self.keepalive_log(f"EXCEPTION: Error in keepalive logger: {e}")
   494→                await asyncio.sleep(1.0)
   495→    
   496→    async def handle_packet(self, data: bytes, addr: Tuple[str, int]):
   497→        """Handle incoming UDP packet"""
   498→        try:
   499→            self.packet_count += 1
   500→            
   501→            # Log every 100th packet to avoid spam, but also log first few
   502→            if self.packet_count <= 10 or self.packet_count % 100 == 0:
   503→                session_count = len(self.sessions)
   504→                self.log(f"RECV: Packet #{self.packet_count} from {addr}: {repr(data[:50])} (sessions: {session_count})")
   505→            
   506→            parts = self.parse_message(data)
   507→            if not parts or not self.validate_message(parts):
   508→                # Silently ignore invalid packets as per LRCP spec
   509→                self.invalid_packet_count += 1
   510→                self.update_activity_if_possible(parts, addr)
   511→                return
   512→            
   513→            if self.packet_count <= 10:  # Log first few valid messages
   514→                self.log(f"PROCESS: Valid message type '{parts[0]}' with {len(parts)} parts")
   515→            
   516→            msg_type = parts[0]
   517→            
   518→            if msg_type == 'connect':
   519→                session_id = int(parts[1])
   520→                await self.handle_connect(session_id, addr)
   521→                
   522→            elif msg_type == 'data':
   523→                session_id = int(parts[1])
   524→                pos = int(parts[2])
   525→                data_content = parts[3]
   526→                await self.handle_data(session_id, pos, data_content, addr)
   527→                
   528→            elif msg_type == 'ack':
   529→                session_id = int(parts[1])
   530→                length = int(parts[2])
   531→                await self.handle_ack(session_id, length, addr)
   532→                
   533→            elif msg_type == 'close':
   534→                session_id = int(parts[1])
   535→                await self.handle_close(session_id, addr)
   536→                
   537→        except Exception as e:
   538→            self.keepalive_log(f"EXCEPTION: Error handling packet from {addr}: {e}")
   539→            import traceback
   540→            traceback.print_exc()
   541→    
   542→    async def run(self):
   543→        """Main server run method"""
   544→        self.running = True
   545→        self.start_time = time.time()
   546→        self.last_keepalive = time.time()
   547→        
   548→        self.log(f"SERVER: Starting asyncio server on {self.host}:{self.port}")
   549→        
   550→        # Create UDP server
   551→        loop = asyncio.get_running_loop()
   552→        transport, protocol = await loop.create_datagram_endpoint(
   553→            lambda: LRCPProtocol(self), 
   554→            local_addr=(self.host, self.port)
   555→        )
   556→        
   557→        self.transport = transport
   558→        
   559→        # Start background tasks
   560→        self.cleanup_task = asyncio.create_task(self.cleanup_sessions())
   561→        self.keepalive_task = asyncio.create_task(self.keepalive_logger())
   562→        
   563→        if __name__ == '__main__':
   564→            print(f"LRCP Line Reversal Server listening on {self.host}:{self.port}")
   565→        
   566→        self.keepalive_log("Server started and ready to receive packets")
   567→        
   568→        try:
   569→            # Wait for tasks to complete (they run forever until cancelled)
   570→            await asyncio.gather(self.cleanup_task, self.keepalive_task)
   571→        except asyncio.CancelledError:
   572→            pass
   573→        finally:
   574→            transport.close()
   575→    
   576→    def stop(self):
   577→        """Stop the server and cleanup"""
   578→        self.keepalive_log(f"SERVER_STOP: Server stopping. Final session count: {len(self.sessions)}")
   579→        for session_id, session in self.sessions.items():
   580→            age = time.time() - session.last_activity
   581→            self.keepalive_log(f"SERVER_STOP: Session {session_id} active at shutdown (age={age:.1f}s)")
   582→        
   583→        self.running = False
   584→        if self.cleanup_task:
   585→            self.cleanup_task.cancel()
   586→        if self.keepalive_task:
   587→            self.keepalive_task.cancel()
   588→        if self.transport:
   589→            self.transport.close()
   590→
   591→
   592→# Compatibility alias for existing tests
   593→LRCPServer = AsyncLRCPServer
   594→
   595→
   596→async def main():
   597→    import sys
   598→    
   599→    port = 8080
   600→    if len(sys.argv) > 1:
   601→        port = int(sys.argv[1])
   602→    
   603→    server = AsyncLRCPServer(port=port)
   604→    try:
   605→        await server.run()
   606→    except KeyboardInterrupt:
   607→        print("\nShutting down server...")
   608→        server.stop()
   609→
   610→
   611→if __name__ == '__main__':
   612→    asyncio.run(main())

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

     1→#!/usr/bin/env python3
     2→
     3→import unittest
     4→import socket
     5→import threading
     6→import time
     7→from server import LRCPServer, Session
     8→
     9→
    10→class TestLRCPServer(unittest.TestCase):
    11→    def setUp(self):
    12→        # Create server with a specific port to avoid double binding
    13→        self.server = LRCPServer(host='127.0.0.1', port=0)
    14→        self.server_addr = self.server.socket.getsockname()
    15→        
    16→        self.client_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    17→        self.client_socket.settimeout(5.0)
    18→        
    19→        self.server_thread = threading.Thread(target=self.server.run, daemon=True)
    20→        self.server_thread.start()
    21→        time.sleep(0.1)  # Let server start
    22→    
    23→    def tearDown(self):
    24→        self.server.stop()
    25→        self.client_socket.close()
    26→    
    27→    def send_and_receive(self, message: str, expect_response: bool = True):
    28→        self.client_socket.sendto(message.encode('ascii'), self.server_addr)
    29→        if expect_response:
    30→            try:
    31→                data, addr = self.client_socket.recvfrom(1024)
    32→                return data.decode('ascii')
    33→            except socket.timeout:
    34→                return None
    35→        return None
    36→    
    37→    def test_message_parsing(self):
    38→        # Test valid message parsing
    39→        parts = self.server.parse_message(b'/connect/12345/')
    40→        self.assertEqual(parts, ['connect', '12345'])
    41→        
    42→        parts = self.server.parse_message(b'/data/123/0/hello/')
    43→        self.assertEqual(parts, ['data', '123', '0', 'hello'])
    44→        
    45→        # Test invalid messages
    46→        self.assertIsNone(self.server.parse_message(b'invalid'))
    47→        self.assertIsNone(self.server.parse_message(b'/invalid'))
    48→        self.assertIsNone(self.server.parse_message(b'invalid/'))
    49→        self.assertIsNone(self.server.parse_message(b'/' + b'x' * 1000))
    50→    
    51→    def test_message_validation(self):
    52→        # Valid messages
    53→        self.assertTrue(self.server.validate_message(['connect', '12345']))
    54→        self.assertTrue(self.server.validate_message(['data', '123', '0', 'hello']))
    55→        self.assertTrue(self.server.validate_message(['ack', '123', '5']))
    56→        self.assertTrue(self.server.validate_message(['close', '123']))
    57→        
    58→        # Invalid messages
    59→        self.assertFalse(self.server.validate_message(['invalid']))
    60→        self.assertFalse(self.server.validate_message(['connect']))
    61→        self.assertFalse(self.server.validate_message(['connect', 'invalid']))
    62→        self.assertFalse(self.server.validate_message(['connect', '-1']))
    63→        self.assertFalse(self.server.validate_message(['connect', '2147483648']))
    64→        self.assertFalse(self.server.validate_message(['data', '123', '0']))
    65→        self.assertFalse(self.server.validate_message(['ack', '123']))
    66→        self.assertFalse(self.server.validate_message(['close']))
    67→    
    68→    def test_escape_unescape(self):
    69→        # Test basic escaping
    70→        self.assertEqual(self.server.escape_data('hello/world'), r'hello\/world')
    71→        self.assertEqual(self.server.escape_data('hello\\world'), r'hello\\world')
    72→        self.assertEqual(self.server.escape_data('hello/world\\test'), r'hello\/world\\test')
    73→        
    74→        # Test unescaping
    75→        self.assertEqual(self.server.unescape_data(r'hello\/world'), 'hello/world')
    76→        self.assertEqual(self.server.unescape_data(r'hello\\world'), 'hello\\world')
    77→        self.assertEqual(self.server.unescape_data(r'hello\/world\\test'), 'hello/world\\test')
    78→        
    79→        # Round trip
    80→        original = 'hello/world\\test/more'
    81→        escaped = self.server.escape_data(original)
    82→        unescaped = self.server.unescape_data(escaped)
    83→        self.assertEqual(original, unescaped)
    84→    
    85→    def test_connect_message(self):
    86→        # Test successful connect
    87→        response = self.send_and_receive('/connect/12345/')
    88→        self.assertEqual(response, '/ack/12345/0/')
    89→        self.assertIn(12345, self.server.sessions)
    90→        
    91→        # Test duplicate connect
    92→        response = self.send_and_receive('/connect/12345/')
    93→        self.assertEqual(response, '/ack/12345/0/')
    94→        self.assertIn(12345, self.server.sessions)
    95→    
    96→    def test_simple_line_reversal(self):
    97→        # Connect
    98→        response = self.send_and_receive('/connect/12345/')
    99→        self.assertEqual(response, '/ack/12345/0/')
   100→        
   101→        # Send data - "hello\n" should be 6 chars
   102→        response = self.send_and_receive('/data/12345/0/hello\n/')
   103→        # The data is "hello\n" = 6 characters
   104→        self.assertEqual(response, '/ack/12345/6/')
   105→        
   106→        # Should receive reversed line
   107→        try:
   108→            data, addr = self.client_socket.recvfrom(1024)
   109→            response = data.decode('ascii')
   110→            # Should be /data/12345/0/olleh\n/ (escaped)
   111→            self.assertTrue(response.startswith('/data/12345/0/'))
   112→            self.assertTrue('olleh' in response)
   113→        except socket.timeout:
   114→            self.fail("Did not receive reversed line")
   115→    
   116→    def test_multiple_lines(self):
   117→        # Connect
   118→        response = self.send_and_receive('/connect/12345/')
   119→        self.assertEqual(response, '/ack/12345/0/')
   120→        
   121→        # Send first line
   122→        response = self.send_and_receive('/data/12345/0/hello\n/')
   123→        self.assertEqual(response, '/ack/12345/6/')
   124→        
   125→        # Receive first response
   126→        data, addr = self.client_socket.recvfrom(1024)
   127→        response1 = data.decode('ascii')
   128→        
   129→        # Send second line  
   130→        response = self.send_and_receive('/data/12345/6/world\n/')
   131→        self.assertEqual(response, '/ack/12345/12/')
   132→        
   133→        # Receive second response
   134→        data, addr = self.client_socket.recvfrom(1024)
   135→        response2 = data.decode('ascii')
   136→        
   137→        # Check responses contain reversed text
   138→        self.assertTrue('olleh' in response1)
   139→        self.assertTrue('dlrow' in response2)
   140→    
   141→    def test_data_with_escaping(self):
   142→        # Connect
   143→        response = self.send_and_receive('/connect/12345/')
   144→        self.assertEqual(response, '/ack/12345/0/')
   145→        
   146→        # Send data with forward slash (escaped) 
   147→        # The message format: /data/SESSION/POS/DATA/ - so we need to use the proper message
   148→        data_to_send = 'hello/world'  # What we want to send (unescaped) - 11 chars
   149→        escaped_data = data_to_send.replace('/', r'\/')  # Escape for LRCP
   150→        response = self.send_and_receive(f'/data/12345/0/{escaped_data}/')
   151→        self.assertEqual(response, '/ack/12345/11/')
   152→        
   153→        # Since there's no newline, no complete line to reverse
   154→        # So we don't expect any response data from the server
   155→    
   156→    def test_close_message(self):
   157→        # Connect
   158→        response = self.send_and_receive('/connect/12345/')
   159→        self.assertEqual(response, '/ack/12345/0/')
   160→        self.assertIn(12345, self.server.sessions)
   161→        
   162→        # Close
   163→        response = self.send_and_receive('/close/12345/')
   164→        self.assertEqual(response, '/close/12345/')
   165→        self.assertNotIn(12345, self.server.sessions)
   166→    
   167→    def test_data_without_session(self):
   168→        # Send data without establishing session
   169→        response = self.send_and_receive('/data/99999/0/hello/')
   170→        self.assertEqual(response, '/close/99999/')
   171→    
   172→    def test_ack_without_session(self):
   173→        # Send ack without establishing session
   174→        response = self.send_and_receive('/ack/99999/5/')
   175→        self.assertEqual(response, '/close/99999/')
   176→    
   177→    def test_invalid_messages_ignored(self):
   178→        # Send various invalid messages - should be ignored
   179→        response = self.send_and_receive('invalid message', expect_response=False)
   180→        self.assertIsNone(response)
   181→        
   182→        response = self.send_and_receive('/invalid/', expect_response=False)
   183→        self.assertIsNone(response)
   184→        
   185→        response = self.send_and_receive('/connect/', expect_response=False)
   186→        self.assertIsNone(response)
   187→    
   188→    def test_session_class(self):
   189→        session = Session(12345, ('127.0.0.1', 8080))
   190→        self.assertEqual(session.session_id, 12345)
   191→        self.assertEqual(session.addr, ('127.0.0.1', 8080))
   192→        self.assertEqual(session.received_length, 0)
   193→        self.assertEqual(session.sent_length, 0)
   194→        self.assertEqual(session.buffer, "")
   195→        
   196→        # Test activity update
   197→        old_time = session.last_activity
   198→        time.sleep(0.01)
   199→        session.update_activity()
   200→        self.assertGreater(session.last_activity, old_time)
   201→    
   202→    def test_large_session_id(self):
   203→        # Test with maximum valid session ID
   204→        max_id = 2147483647
   205→        response = self.send_and_receive(f'/connect/{max_id}/')
   206→        self.assertEqual(response, f'/ack/{max_id}/0/')
   207→        
   208→        # Test with invalid session ID (too large)
   209→        invalid_id = 2147483648
   210→        response = self.send_and_receive(f'/connect/{invalid_id}/', expect_response=False)
   211→        self.assertIsNone(response)
   212→    
   213→    def test_long_line_reversal(self):
   214→        # Connect
   215→        response = self.send_and_receive('/connect/12345/')
   216→        self.assertEqual(response, '/ack/12345/0/')
   217→        
   218→        # Send a long line (but under 10,000 chars as per spec)
   219→        long_text = 'a' * 100
   220→        # Need to properly format the message without literal newlines breaking it
   221→        # Use a different approach - send without newline and test length
   222→        response = self.send_and_receive(f'/data/12345/0/{long_text}/')
   223→        self.assertEqual(response, '/ack/12345/100/')
   224→        
   225→        # Without newline, there's no complete line to reverse
   226→        # So we don't expect any response data from the server
   227→        # The test passes if we can handle the long data without issues
   228→
   229→
   230→class TestEdgeCases(unittest.TestCase):
   231→    def setUp(self):
   232→        self.server = LRCPServer()
   233→    
   234→    def test_empty_line_reversal(self):
   235→        session = Session(12345, ('127.0.0.1', 8080))
   236→        
   237→        # Process empty line
   238→        self.server.process_new_data(session, '\n')
   239→        
   240→        # Should have sent empty response
   241→        self.assertEqual(len(session.sent_data), 1)
   242→        self.assertEqual(session.sent_data[0], '\n')
   243→    
   244→    def test_partial_lines(self):
   245→        session = Session(12345, ('127.0.0.1', 8080))
   246→        
   247→        # Send partial data without newline
   248→        self.server.process_new_data(session, 'hello')
   249→        self.assertEqual(session.buffer, 'hello')
   250→        self.assertEqual(len(session.sent_data), 0)
   251→        
   252→        # Complete the line
   253→        self.server.process_new_data(session, ' world\n')
   254→        self.assertEqual(session.buffer, '')
   255→        self.assertEqual(len(session.sent_data), 1)
   256→        self.assertEqual(session.sent_data[0], 'dlrow olleh\n')
   257→    
   258→    def test_multiple_lines_in_one_message(self):
   259→        session = Session(12345, ('127.0.0.1', 8080))
   260→        
   261→        # Send multiple lines at once
   262→        self.server.process_new_data(session, 'hello\nworld\n')
   263→        
   264→        # Should have processed both lines
   265→        self.assertEqual(len(session.sent_data), 2)
   266→        self.assertEqual(session.sent_data[0], 'olleh\n')
   267→        self.assertEqual(session.sent_data[6], 'dlrow\n')
   268→
   269→
   270→if __name__ == '__main__':
   271→    # Import the retransmission bug tests
   272→    from test_retransmission_bug import TestRetransmissionBug
   273→    unittest.main()

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

The file /home/smite/dev/protohackers/7-line-reversal/test_server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   266→        self.assertEqual(session.sent_data[0], 'olleh\n')
   267→        self.assertEqual(session.sent_data[6], 'dlrow\n')
   268→
   269→
   270→class TestLargePackets(unittest.TestCase):
   271→    def setUp(self):
   272→        # Create server with AsyncLRCPServer since that's what's being used
   273→        from server import AsyncLRCPServer
   274→        import asyncio
   275→        
   276→        self.server = AsyncLRCPServer(host='127.0.0.1', port=0)
   277→        self.client_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
   278→        self.client_socket.settimeout(10.0)  # Longer timeout for large data
   279→        
   280→        # Start server in background
   281→        self.loop = asyncio.new_event_loop()
   282→        self.server_thread = threading.Thread(
   283→            target=self._run_server_in_thread,
   284→            daemon=True
   285→        )
   286→        self.server_thread.start()
   287→        time.sleep(0.2)  # Let server start
   288→        
   289→        # Get server address after it starts
   290→        self.server_addr = ('127.0.0.1', 8080)  # Default port since we set to 0
   291→    
   292→    def _run_server_in_thread(self):
   293→        asyncio.set_event_loop(self.loop)
   294→        try:
   295→            self.loop.run_until_complete(self.server.run())
   296→        except:
   297→            pass
   298→    
   299→    def tearDown(self):
   300→        self.server.stop()
   301→        self.client_socket.close()
   302→        if hasattr(self, 'loop'):
   303→            self.loop.call_soon_threadsafe(self.loop.stop)
   304→    
   305→    def send_message(self, message: str):
   306→        """Send a message to the server"""
   307→        self.client_socket.sendto(message.encode('ascii'), self.server_addr)
   308→    
   309→    def receive_message(self, timeout=5.0):
   310→        """Receive a message from the server"""
   311→        old_timeout = self.client_socket.gettimeout()
   312→        self.client_socket.settimeout(timeout)
   313→        try:
   314→            data, addr = self.client_socket.recvfrom(1024)
   315→            return data.decode('ascii')
   316→        except socket.timeout:
   317→            return None
   318→        finally:
   319→            self.client_socket.settimeout(old_timeout)
   320→    
   321→    def test_40kb_data_transfer_with_packet_validation(self):
   322→        """Test transferring 40KB of data and validate packet sizes are under 1000 bytes"""
   323→        
   324→        # Connect to server
   325→        self.send_message('/connect/12345/')
   326→        response = self.receive_message()
   327→        self.assertEqual(response, '/ack/12345/0/')
   328→        
   329→        # Create 40KB of test data - multiple lines to ensure proper reversal
   330→        # Each line is about 80 chars + newline = 81 chars
   331→        # 40KB / 81 chars ≈ 505 lines
   332→        line_length = 79  # 79 chars + newline = 80 chars per line
   333→        num_lines = (40 * 1024) // (line_length + 1)  # Calculate number of lines needed
   334→        
   335→        test_lines = []
   336→        for i in range(num_lines):
   337→            # Create unique content for each line to verify proper reversal
   338→            line_content = f"Line{i:04d}" + "x" * (line_length - 8)  # Pad to exact length
   339→            test_lines.append(line_content)
   340→        
   341→        # Join all lines with newlines
   342→        large_data = '\n'.join(test_lines) + '\n'
   343→        actual_size = len(large_data)
   344→        
   345→        print(f"Created test data: {actual_size} bytes, {len(test_lines)} lines")
   346→        self.assertGreaterEqual(actual_size, 40 * 1024)  # At least 40KB
   347→        
   348→        # Send the large data - we need to chunk it ourselves since LRCP has packet size limits
   349→        chunk_size = 800  # Conservative chunk size to stay under 1000 byte packet limit
   350→        pos = 0
   351→        sent_packets = 0
   352→        
   353→        while pos < len(large_data):
   354→            chunk = large_data[pos:pos + chunk_size]
   355→            escaped_chunk = chunk.replace('\\', r'\\').replace('/', r'\/')
   356→            
   357→            # Create the LRCP data message
   358→            message = f'/data/12345/{pos}/{escaped_chunk}/'
   359→            
   360→            # Validate packet size
   361→            packet_size = len(message.encode('ascii'))
   362→            self.assertLess(packet_size, 1000, 
   363→                          f"Packet size {packet_size} exceeds 1000 bytes at position {pos}")
   364→            
   365→            # Send the chunk
   366→            self.send_message(message)
   367→            sent_packets += 1
   368→            
   369→            # Wait for acknowledgment
   370→            ack_response = self.receive_message(timeout=2.0)
   371→            expected_ack_pos = pos + len(chunk)
   372→            expected_ack = f'/ack/12345/{expected_ack_pos}/'
   373→            self.assertEqual(ack_response, expected_ack,
   374→                           f"Expected ack for position {expected_ack_pos}, got {ack_response}")
   375→            
   376→            pos += len(chunk)
   377→        
   378→        print(f"Sent {sent_packets} packets, total {pos} bytes")
   379→        
   380→        # Now collect all the reversed responses
   381→        received_responses = []
   382→        start_time = time.time()
   383→        
   384→        # We should receive one response for each line that was sent
   385→        expected_responses = len(test_lines)
   386→        
   387→        while len(received_responses) < expected_responses and time.time() - start_time < 15:
   388→            response = self.receive_message(timeout=1.0)
   389→            if response and response.startswith('/data/12345/'):
   390→                # Validate response packet size
   391→                response_size = len(response.encode('ascii'))
   392→                self.assertLess(response_size, 1000,
   393→                              f"Response packet size {response_size} exceeds 1000 bytes")
   394→                
   395→                received_responses.append(response)
   396→                
   397→                # Send acknowledgment for the response
   398→                # Parse the response to get position and length
   399→                parts = response.split('/')
   400→                if len(parts) >= 4:
   401→                    resp_pos = int(parts[3])
   402→                    resp_data = '/'.join(parts[4:-1])  # Join back the data part
   403→                    # Unescape the data
   404→                    unescaped_data = resp_data.replace(r'\/', '/').replace(r'\\', '\\')
   405→                    ack_pos = resp_pos + len(unescaped_data)
   406→                    self.send_message(f'/ack/12345/{ack_pos}/')
   407→        
   408→        print(f"Received {len(received_responses)} response packets")
   409→        
   410→        # Verify we got responses for all lines
   411→        self.assertEqual(len(received_responses), expected_responses,
   412→                        f"Expected {expected_responses} responses, got {len(received_responses)}")
   413→        
   414→        # Verify the content was properly reversed
   415→        # Parse and collect all reversed content
   416→        reversed_content = []
   417→        
   418→        for response in received_responses:
   419→            parts = response.split('/')
   420→            if len(parts) >= 4:
   421→                resp_data = '/'.join(parts[4:-1])  # Join back the data part
   422→                # Unescape the data
   423→                unescaped_data = resp_data.replace(r'\/', '/').replace(r'\\', '\\')
   424→                reversed_content.append(unescaped_data.rstrip('\n'))  # Remove trailing newline
   425→        
   426→        # Sort by the actual reversed content to match original order
   427→        # Since responses might arrive out of order
   428→        reversed_content.sort()
   429→        
   430→        # Verify each line was properly reversed
   431→        for i, original_line in enumerate(test_lines):
   432→            expected_reversed = original_line[::-1]
   433→            # Find matching reversed line
   434→            found = False
   435→            for reversed_line in reversed_content:
   436→                if reversed_line == expected_reversed:
   437→                    found = True
   438→                    break
   439→            
   440→            self.assertTrue(found, 
   441→                          f"Could not find reversed version of line {i}: '{original_line}' -> expected '{expected_reversed}'")
   442→        
   443→        print("Successfully verified large data transfer with proper packet size limits and content reversal")
   444→
   445→
   446→if __name__ == '__main__':
   447→    # Import the retransmission bug tests
   448→    try:
   449→        from test_retransmission_bug import TestRetransmissionBug
   450→    except ImportError:
   451→        pass
   452→    unittest.main()

/home/smite/dev/protohackers/7-line-reversal/server.py:220: SyntaxWarning: invalid escape sequence '\/'
  """Check if data contains unescaped forward slashes (which should be escaped as \/)"""
test_40kb_data_transfer_with_packet_validation (test_server.TestLargePackets.test_40kb_data_transfer_with_packet_validation)
Test transferring 40KB of data and validate packet sizes are under 1000 bytes ... Exception in thread Thread-1 (_run_server_in_thread):
Traceback (most recent call last):
  File "/usr/lib/python3.13/threading.py", line 1041, in _bootstrap_inner
    self.run()
    ~~~~~~~~^^
  File "/usr/lib/python3.13/threading.py", line 992, in run
    self._target(*self._args, **self._kwargs)
    ~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/smite/dev/protohackers/7-line-reversal/test_server.py", line 293, in _run_server_in_thread
    asyncio.set_event_loop(self.loop)
    ^^^^^^^
NameError: name 'asyncio' is not defined. Did you forget to import 'asyncio'?
FAIL
[   5.202s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 0

======================================================================
FAIL: test_40kb_data_transfer_with_packet_validation (test_server.TestLargePackets.test_40kb_data_transfer_with_packet_validation)
Test transferring 40KB of data and validate packet sizes are under 1000 bytes
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_server.py", line 327, in test_40kb_data_transfer_with_packet_validation
    self.assertEqual(response, '/ack/12345/0/')
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: None != '/ack/12345/0/'

----------------------------------------------------------------------
Ran 1 test in 5.203s

FAILED (failures=1)

The file /home/smite/dev/protohackers/7-line-reversal/test_server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   266→        self.assertEqual(session.sent_data[0], 'olleh\n')
   267→        self.assertEqual(session.sent_data[6], 'dlrow\n')
   268→
   269→
   270→class TestLargePackets(unittest.TestCase):
   271→    def setUp(self):
   272→        # Create server with AsyncLRCPServer since that's what's being used
   273→        from server import AsyncLRCPServer
   274→        import asyncio
   275→        
   276→        # Find an available port
   277→        import socket as sock_mod
   278→        temp_sock = sock_mod.socket(sock_mod.AF_INET, sock_mod.SOCK_DGRAM)
   279→        temp_sock.bind(('127.0.0.1', 0))
   280→        self.server_port = temp_sock.getsockname()[1]
   281→        temp_sock.close()
   282→        
   283→        self.server = AsyncLRCPServer(host='127.0.0.1', port=self.server_port)
   284→        self.client_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
   285→        self.client_socket.settimeout(10.0)  # Longer timeout for large data
   286→        
   287→        # Start server in background
   288→        self.loop = asyncio.new_event_loop()
   289→        self.server_thread = threading.Thread(
   290→            target=self._run_server_in_thread,
   291→            daemon=True
   292→        )
   293→        self.server_thread.start()
   294→        time.sleep(0.5)  # Let server start
   295→        
   296→        # Get server address after it starts
   297→        self.server_addr = ('127.0.0.1', self.server_port)
   298→    
   299→    def _run_server_in_thread(self):
   300→        import asyncio
   301→        asyncio.set_event_loop(self.loop)
   302→        try:
   303→            self.loop.run_until_complete(self.server.run())
   304→        except:
   305→            pass
   306→    
   307→    def tearDown(self):
   308→        self.server.stop()
   309→        self.client_socket.close()

test_40kb_data_transfer_with_packet_validation (test_server.TestLargePackets.test_40kb_data_transfer_with_packet_validation)
Test transferring 40KB of data and validate packet sizes are under 1000 bytes ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 38032). Total sessions: 1 (created=1, closed=0, expired=0)
FAIL
[   0.504s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   0.504s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.0s)

======================================================================
FAIL: test_40kb_data_transfer_with_packet_validation (test_server.TestLargePackets.test_40kb_data_transfer_with_packet_validation)
Test transferring 40KB of data and validate packet sizes are under 1000 bytes
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_server.py", line 381, in test_40kb_data_transfer_with_packet_validation
    self.assertEqual(ack_response, expected_ack,
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^
                   f"Expected ack for position {expected_ack_pos}, got {ack_response}")
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: '/data/12345/0/xxxxxxxxxxxxxxxxxxxxxxxxxxxx[50 chars]L\n/' != '/ack/12345/1600/'
+ /ack/12345/1600/
- /data/12345/0/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx0000eniL
- /
 : Expected ack for position 1600, got /data/12345/0/xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx0000eniL
/

----------------------------------------------------------------------
Ran 1 test in 0.505s

FAILED (failures=1)
Task was destroyed but it is pending!
task: <Task pending name='Task-6' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-7' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-8' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-9' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-10' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-11' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-12' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-13' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-14' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-15' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-17' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-18' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-19' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-20' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-21' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-22' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-23' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-24' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-25' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-26' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>

Created test data: 40960 bytes, 512 lines

The file /home/smite/dev/protohackers/7-line-reversal/test_server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   352→        
   353→        print(f"Created test data: {actual_size} bytes, {len(test_lines)} lines")
   354→        self.assertGreaterEqual(actual_size, 40 * 1024)  # At least 40KB
   355→        
   356→        # Send the large data - we need to chunk it ourselves since LRCP has packet size limits
   357→        chunk_size = 800  # Conservative chunk size to stay under 1000 byte packet limit
   358→        pos = 0
   359→        sent_packets = 0
   360→        received_responses = []
   361→        
   362→        while pos < len(large_data):
   363→            chunk = large_data[pos:pos + chunk_size]
   364→            escaped_chunk = chunk.replace('\\', r'\\').replace('/', r'\/')
   365→            
   366→            # Create the LRCP data message
   367→            message = f'/data/12345/{pos}/{escaped_chunk}/'
   368→            
   369→            # Validate packet size
   370→            packet_size = len(message.encode('ascii'))
   371→            self.assertLess(packet_size, 1000, 
   372→                          f"Packet size {packet_size} exceeds 1000 bytes at position {pos}")
   373→            
   374→            # Send the chunk
   375→            self.send_message(message)
   376→            sent_packets += 1
   377→            
   378→            # Process incoming messages (could be acks or data responses)
   379→            messages_received = 0
   380→            while messages_received < 10:  # Limit to prevent infinite loop
   381→                response = self.receive_message(timeout=0.1)
   382→                if response is None:
   383→                    break
   384→                messages_received += 1
   385→                
   386→                if response.startswith('/ack/12345/'):
   387→                    # This is an acknowledgment - verify it
   388→                    expected_ack_pos = pos + len(chunk)
   389→                    expected_ack = f'/ack/12345/{expected_ack_pos}/'
   390→                    self.assertEqual(response, expected_ack,
   391→                                   f"Expected ack for position {expected_ack_pos}, got {response}")
   392→                elif response.startswith('/data/12345/'):
   393→                    # This is a data response (reversed line) - collect it
   394→                    response_size = len(response.encode('ascii'))
   395→                    self.assertLess(response_size, 1000,
   396→                                  f"Response packet size {response_size} exceeds 1000 bytes")
   397→                    received_responses.append(response)
   398→                    
   399→                    # Send acknowledgment for the response
   400→                    parts = response.split('/')
   401→                    if len(parts) >= 4:
   402→                        resp_pos = int(parts[3])
   403→                        resp_data = '/'.join(parts[4:-1])  # Join back the data part
   404→                        # Unescape the data
   405→                        unescaped_data = resp_data.replace(r'\/', '/').replace(r'\\', '\\')
   406→                        ack_pos = resp_pos + len(unescaped_data)
   407→                        self.send_message(f'/ack/12345/{ack_pos}/')
   408→            
   409→            pos += len(chunk)
   410→        
   411→        print(f"Sent {sent_packets} packets, total {pos} bytes")
   412→        
   413→        # Now collect all the reversed responses
   414→        received_responses = []
   415→        start_time = time.time()

The file /home/smite/dev/protohackers/7-line-reversal/test_server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   407→                        self.send_message(f'/ack/12345/{ack_pos}/')
   408→            
   409→            pos += len(chunk)
   410→        
   411→        print(f"Sent {sent_packets} packets, total {pos} bytes")
   412→        
   413→        # Collect any remaining reversed responses
   414→        start_time = time.time()
   415→        expected_responses = len(test_lines)
   416→        
   417→        while len(received_responses) < expected_responses and time.time() - start_time < 10:
   418→            response = self.receive_message(timeout=0.5)
   419→            if response and response.startswith('/data/12345/'):
   420→                # Validate response packet size
   421→                response_size = len(response.encode('ascii'))
   422→                self.assertLess(response_size, 1000,
   423→                              f"Response packet size {response_size} exceeds 1000 bytes")
   424→                
   425→                received_responses.append(response)
   426→                
   427→                # Send acknowledgment for the response
   428→                parts = response.split('/')
   429→                if len(parts) >= 4:
   430→                    resp_pos = int(parts[3])
   431→                    resp_data = '/'.join(parts[4:-1])  # Join back the data part
   432→                    # Unescape the data
   433→                    unescaped_data = resp_data.replace(r'\/', '/').replace(r'\\', '\\')
   434→                    ack_pos = resp_pos + len(unescaped_data)
   435→                    self.send_message(f'/ack/12345/{ack_pos}/')
   436→        
   437→        print(f"Received {len(received_responses)} response packets")
   438→        
   439→        # Verify we got responses for all lines
   440→        self.assertEqual(len(received_responses), expected_responses,
   441→                        f"Expected {expected_responses} responses, got {len(received_responses)}")

test_40kb_data_transfer_with_packet_validation (test_server.TestLargePackets.test_40kb_data_transfer_with_packet_validation)
Test transferring 40KB of data and validate packet sizes are under 1000 bytes ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 51767). Total sessions: 1 (created=1, closed=0, expired=0)
FAIL
[   0.526s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   0.526s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.0s)

======================================================================
FAIL: test_40kb_data_transfer_with_packet_validation (test_server.TestLargePackets.test_40kb_data_transfer_with_packet_validation)
Test transferring 40KB of data and validate packet sizes are under 1000 bytes
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_server.py", line 390, in test_40kb_data_transfer_with_packet_validation
    self.assertEqual(response, expected_ack,
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^
                   f"Expected ack for position {expected_ack_pos}, got {response}")
                   ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: '/ack/12345/8800/' != '/ack/12345/9600/'
- /ack/12345/8800/
?            ^^
+ /ack/12345/9600/
?            ^^
 : Expected ack for position 9600, got /ack/12345/8800/

----------------------------------------------------------------------
Ran 1 test in 0.527s

FAILED (failures=1)
Task was destroyed but it is pending!
task: <Task pending name='Task-206' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-207' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-208' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-209' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-210' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-211' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-212' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-213' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-214' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-215' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-227' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-228' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-229' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-230' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-231' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-232' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-233' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-234' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-235' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-236' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:365> wait_for=<Future pending cb=[Task.task_wakeup()]>>

Created test data: 40960 bytes, 512 lines

The file /home/smite/dev/protohackers/7-line-reversal/test_server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   325→            return None
   326→        finally:
   327→            self.client_socket.settimeout(old_timeout)
   328→    
   329→    def test_40kb_data_transfer_with_packet_validation(self):
   330→        """Test transferring 40KB of data and validate packet sizes are under 1000 bytes"""
   331→        
   332→        # Connect to server
   333→        self.send_message('/connect/12345/')
   334→        response = self.receive_message()
   335→        self.assertEqual(response, '/ack/12345/0/')
   336→        
   337→        # Create 40KB of test data - multiple lines to ensure proper reversal
   338→        # Use shorter lines to ensure they fit in small packets
   339→        line_length = 50  # 50 chars + newline = 51 chars per line
   340→        num_lines = (40 * 1024) // (line_length + 1)  # Calculate number of lines needed
   341→        
   342→        test_lines = []
   343→        for i in range(num_lines):
   344→            # Create unique content for each line to verify proper reversal
   345→            line_content = f"L{i:04d}" + "x" * (line_length - 5)  # Pad to exact length
   346→            test_lines.append(line_content)
   347→        
   348→        # Join all lines with newlines
   349→        large_data = '\n'.join(test_lines) + '\n'
   350→        actual_size = len(large_data)
   351→        
   352→        print(f"Created test data: {actual_size} bytes, {len(test_lines)} lines")
   353→        self.assertGreaterEqual(actual_size, 40 * 1024)  # At least 40KB
   354→        
   355→        # Send the large data - we need to chunk it ourselves since LRCP has packet size limits
   356→        chunk_size = 700  # Conservative chunk size to stay under 1000 byte packet limit
   357→        pos = 0
   358→        sent_packets = 0
   359→        received_responses = []
   360→        
   361→        while pos < len(large_data):
   362→            chunk = large_data[pos:pos + chunk_size]
   363→            escaped_chunk = chunk.replace('\\', r'\\').replace('/', r'\/')
   364→            
   365→            # Create the LRCP data message
   366→            message = f'/data/12345/{pos}/{escaped_chunk}/'
   367→            
   368→            # Validate packet size
   369→            packet_size = len(message.encode('ascii'))
   370→            self.assertLess(packet_size, 1000, 
   371→                          f"Packet size {packet_size} exceeds 1000 bytes at position {pos}")
   372→            
   373→            # Send the chunk
   374→            self.send_message(message)
   375→            sent_packets += 1
   376→            
   377→            # Process incoming messages (acks and data responses)
   378→            while True:
   379→                response = self.receive_message(timeout=0.1)
   380→                if response is None:
   381→                    break
   382→                
   383→                # Validate packet size for all responses
   384→                response_size = len(response.encode('ascii'))
   385→                self.assertLess(response_size, 1000,
   386→                              f"Response packet size {response_size} exceeds 1000 bytes")
   387→                
   388→                if response.startswith('/ack/12345/'):
   389→                    # This is an acknowledgment - just continue
   390→                    pass
   391→                elif response.startswith('/data/12345/'):
   392→                    # This is a data response (reversed line) - collect it
   393→                    received_responses.append(response)
   394→                    
   395→                    # Send acknowledgment for the response
   396→                    parts = response.split('/')
   397→                    if len(parts) >= 4:
   398→                        resp_pos = int(parts[3])
   399→                        resp_data = '/'.join(parts[4:-1])  # Join back the data part
   400→                        # Unescape the data
   401→                        unescaped_data = resp_data.replace(r'\/', '/').replace(r'\\', '\\')
   402→                        ack_pos = resp_pos + len(unescaped_data)
   403→                        self.send_message(f'/ack/12345/{ack_pos}/')
   404→            
   405→            pos += len(chunk)
   406→        
   407→        print(f"Sent {sent_packets} packets, total {pos} bytes")
   408→        
   409→        # Collect any remaining reversed responses
   410→        start_time = time.time()
   411→        expected_responses = len(test_lines)
   412→        
   413→        while len(received_responses) < expected_responses and time.time() - start_time < 10:
   414→            response = self.receive_message(timeout=0.5)
   415→            if response and response.startswith('/data/12345/'):
   416→                # Validate response packet size
   417→                response_size = len(response.encode('ascii'))
   418→                self.assertLess(response_size, 1000,
   419→                              f"Response packet size {response_size} exceeds 1000 bytes")
   420→                
   421→                received_responses.append(response)
   422→                
   423→                # Send acknowledgment for the response
   424→                parts = response.split('/')
   425→                if len(parts) >= 4:
   426→                    resp_pos = int(parts[3])
   427→                    resp_data = '/'.join(parts[4:-1])  # Join back the data part
   428→                    # Unescape the data
   429→                    unescaped_data = resp_data.replace(r'\/', '/').replace(r'\\', '\\')
   430→                    ack_pos = resp_pos + len(unescaped_data)
   431→                    self.send_message(f'/ack/12345/{ack_pos}/')
   432→        
   433→        print(f"Received {len(received_responses)} response packets")
   434→        print(f"Expected {expected_responses} responses")
   435→        
   436→        # Verify we got a reasonable number of responses
   437→        self.assertGreater(len(received_responses), expected_responses * 0.8,
   438→                          f"Expected at least {int(expected_responses * 0.8)} responses, got {len(received_responses)}")
   439→        
   440→        # Verify the content was properly reversed for the responses we did get
   441→        # Parse and collect all reversed content
   442→        reversed_content = []
   443→        
   444→        for response in received_responses:
   445→            parts = response.split('/')
   446→            if len(parts) >= 4:
   447→                resp_data = '/'.join(parts[4:-1])  # Join back the data part
   448→                # Unescape the data
   449→                unescaped_data = resp_data.replace(r'\/', '/').replace(r'\\', '\\')
   450→                reversed_content.append(unescaped_data.rstrip('\n'))  # Remove trailing newline
   451→        
   452→        # Verify at least some lines were properly reversed
   453→        verified_reversals = 0
   454→        for original_line in test_lines[:100]:  # Check first 100 lines
   455→            expected_reversed = original_line[::-1]
   456→            # Find matching reversed line
   457→            for reversed_line in reversed_content:
   458→                if reversed_line == expected_reversed:
   459→                    verified_reversals += 1
   460→                    break
   461→        
   462→        self.assertGreater(verified_reversals, 50,
   463→                          f"Expected at least 50 proper reversals, got {verified_reversals}")
   464→        
   465→        print(f"Successfully verified {verified_reversals} proper line reversals")
   466→        print("Successfully verified large data transfer with proper packet size limits and content reversal")
   467→
   468→
   469→if __name__ == '__main__':
   470→    # Import the retransmission bug tests

test_40kb_data_transfer_with_packet_validation (test_server.TestLargePackets.test_40kb_data_transfer_with_packet_validation)
Test transferring 40KB of data and validate packet sizes are under 1000 bytes ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 51884). Total sessions: 1 (created=1, closed=0, expired=0)
FAIL
[   0.503s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   0.503s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.0s)

======================================================================
FAIL: test_40kb_data_transfer_with_packet_validation (test_server.TestLargePackets.test_40kb_data_transfer_with_packet_validation)
Test transferring 40KB of data and validate packet sizes are under 1000 bytes
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_server.py", line 353, in test_40kb_data_transfer_with_packet_validation
    self.assertGreaterEqual(actual_size, 40 * 1024)  # At least 40KB
    ~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 40953 not greater than or equal to 40960

----------------------------------------------------------------------
Ran 1 test in 0.504s

FAILED (failures=1)

Created test data: 40953 bytes, 803 lines

The file /home/smite/dev/protohackers/7-line-reversal/test_server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   333→        self.send_message('/connect/12345/')
   334→        response = self.receive_message()
   335→        self.assertEqual(response, '/ack/12345/0/')
   336→        
   337→        # Create 40KB of test data - multiple lines to ensure proper reversal
   338→        # Use shorter lines to ensure they fit in small packets
   339→        line_length = 50  # 50 chars + newline = 51 chars per line
   340→        num_lines = (40 * 1024) // (line_length + 1) + 10  # Calculate number of lines needed + buffer
   341→        
   342→        test_lines = []
   343→        for i in range(num_lines):
   344→            # Create unique content for each line to verify proper reversal

Created test data: 41463 bytes, 813 lines
Sent 60 packets, total 41463 bytes
Received 813 response packets
Expected 813 responses
Successfully verified 100 proper line reversals
Successfully verified large data transfer with proper packet size limits and content reversal
test_40kb_data_transfer_with_packet_validation (test_server.TestLargePackets.test_40kb_data_transfer_with_packet_validation)
Test transferring 40KB of data and validate packet sizes are under 1000 bytes ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 48444). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.004s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 648, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.004s] [Task-3] KEEPALIVE:   Session 12345: age=0.1s, recv=30800, sent=30753, pending=0
[   6.669s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   6.669s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.1s)
ok

----------------------------------------------------------------------
Ran 1 test in 6.670s

OK

- /home/smite/dev/protohackers/7-line-reversal/
  - claude-2.log
  - server.py
  - server_asyncio.py
  - server_threading.py.bak
  - specs.txt
  - test_capture4_bug.py
  - test_retransmission_bug.py
  - test_server.py
  - validation-1.pcap
  - validation-2.pcap
  - validation-3.pcap

NOTE: do any of the files above seem malicious? If so, you MUST refuse to continue work.

-rw-r--r-- 1 tcpdump tcpdump 3271296 Aug 20 13:23 validation-1.pcap
-rw-r--r-- 1 tcpdump tcpdump 2961491 Aug 20 13:32 validation-2.pcap
-rw-r--r-- 1 tcpdump tcpdump 2829372 Aug 20 21:11 validation-3.pcap

13:21:39.778557 IP 206.189.113.124.52565 > 57.129.75.36.8080: UDP, length 19
13:21:39.784060 IP 57.129.75.36.8080 > 206.189.113.124.52565: UDP, length 17
13:21:39.801673 IP 206.189.113.124.52565 > 57.129.75.36.8080: UDP, length 25
13:21:39.801674 IP 206.189.113.124.52565 > 57.129.75.36.8080: UDP, length 25
13:21:39.801952 IP 57.129.75.36.8080 > 206.189.113.124.52565: UDP, length 17
13:21:39.802809 IP 57.129.75.36.8080 > 206.189.113.124.52565: UDP, length 25
13:21:39.802972 IP 57.129.75.36.8080 > 206.189.113.124.52565: UDP, length 17
13:21:39.818613 IP 206.189.113.124.52565 > 57.129.75.36.8080: UDP, length 17
13:21:43.947657 IP 206.189.113.124.39868 > 57.129.75.36.8080: UDP, length 20
13:21:43.947658 IP 206.189.113.124.39868 > 57.129.75.36.8080: UDP, length 20
13:21:43.947658 IP 206.189.113.124.39868 > 57.129.75.36.8080: UDP, length 20
13:21:43.947658 IP 206.189.113.124.39868 > 57.129.75.36.8080: UDP, length 20
13:21:43.947658 IP 206.189.113.124.39868 > 57.129.75.36.8080: UDP, length 19
13:21:43.947658 IP 206.189.113.124.39868 > 57.129.75.36.8080: UDP, length 19
13:21:43.947658 IP 206.189.113.124.39868 > 57.129.75.36.8080: UDP, length 19
13:21:43.947658 IP 206.189.113.124.39868 > 57.129.75.36.8080: UDP, length 19
13:21:43.947699 IP 206.189.113.124.39868 > 57.129.75.36.8080: UDP, length 20
13:21:43.947699 IP 206.189.113.124.39868 > 57.129.75.36.8080: UDP, length 17
13:21:43.948168 IP 57.129.75.36.8080 > 206.189.113.124.39868: UDP, length 18
13:21:43.948332 IP 57.129.75.36.8080 > 206.189.113.124.39868: UDP, length 18
reading from file validation-1.pcap, link-type EN10MB (Ethernet), snapshot length 262144
tcpdump: Unable to write output: Broken pipe

   320→            self.log(f"DATA: Out of order data for session {session_id}, sending duplicate ack {session.last_ack_sent}")
   321→            await self.send_message(addr, f'/ack/{session_id}/{session.last_ack_sent}/')
   322→    
   323→    async def send_data_chunked(self, session: Session, data: str):
   324→        """Send data in chunks to avoid packets over 1000 bytes"""
   325→        max_data_size = 900  # Conservative limit to account for protocol overhead
   326→        
   327→        pos = 0
   328→        while pos < len(data):
   329→            chunk = data[pos:pos + max_data_size]
   330→            escaped_chunk = self.escape_data(chunk)
   331→            
   332→            # Store outgoing data
   333→            session.sent_data[session.sent_length] = chunk
   334→            msg = f'/data/{session.session_id}/{session.sent_length}/{escaped_chunk}/'
   335→            
   336→            # Check if message would be too large
   337→            if len(msg.encode('ascii')) >= 1000:
   338→                # Reduce chunk size and try again
   339→                max_data_size = max_data_size // 2
   340→                continue
   341→            
   342→            self.log(f"PROCESS: Sending chunk to session {session.session_id}: {len(chunk)} bytes at pos {session.sent_length}")
   343→            await self.send_message(session.addr, msg)
   344→            
   345→            # Start retransmission task for this message
   346→            task = asyncio.create_task(self.retransmit_message(session.session_id, session.sent_length, msg))
   347→            session.pending_retransmits[session.sent_length] = (msg, time.time(), 0, task)
   348→            
   349→            pos += len(chunk)
   350→            session.sent_length += len(chunk)
   351→
   352→    async def process_new_data(self, session: Session, data: str):
   353→        self.log(f"PROCESS: Adding {repr(data)} to buffer for session {session.session_id}")
   354→        session.buffer += data
   355→        
   356→        while '\n' in session.buffer:
   357→            line, session.buffer = session.buffer.split('\n', 1)
   358→            reversed_line = line[::-1]
   359→            self.log(f"PROCESS: Reversing line {repr(line)} -> {repr(reversed_line)} for session {session.session_id}")
   360→            
   361→            # Send reversed line back (with newline)
   362→            response = reversed_line + '\n'
   363→            await self.send_data_chunked(session, response)
   364→    
   365→    async def retransmit_message(self, session_id: int, pos: int, msg: str):
   366→        """Handle retransmission of a single message"""
   367→        try:
   368→            retry = 0
   369→            while True:
   370→                await asyncio.sleep(self.retransmit_timeout)
   371→                
   372→                # Check if session still exists and message hasn't been acknowledged
   373→                session = self.sessions.get(session_id)
   374→                if not session or pos not in session.pending_retransmits:
   375→                    return  # Session gone or message acknowledged
   376→                
   377→                retry += 1
   378→                self.log(f"RETRANSMIT: Retransmitting to session {session_id}, pos {pos} (attempt {retry + 1})")
   379→                await self.send_message(session.addr, msg)

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

21:09:19.402873 IP box1.protohackers.com.54446 > vps-6be738f9.vps.ovh.net.8080: UDP, length 19
E../4m@...Sr..q|9.K$......../connect/489050934/
21:09:19.403508 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.54446: UDP, length 17
E..-.V@.@...9.K$..q|.......	/ack/489050934/0/
21:09:19.421990 IP box1.protohackers.com.54446 > vps-6be738f9.vps.ovh.net.8080: UDP, length 25
E..54q@...Sh..q|9.K$.....!../data/489050934/0/hello
/
21:09:19.421990 IP box1.protohackers.com.54446 > vps-6be738f9.vps.ovh.net.8080: UDP, length 25
E..54r@...Sg..q|9.K$.....!../data/489050934/0/hello
/
21:09:19.422221 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.54446: UDP, length 17
E..-.a@.@...9.K$..q|.......	/ack/489050934/6/
21:09:19.422265 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.54446: UDP, length 25
E..5.b@.@..v9.K$..q|.....!../data/489050934/0/olleh
/
21:09:19.422454 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.54446: UDP, length 17
E..-.c@.@..}9.K$..q|.......	/ack/489050934/6/
21:09:19.440255 IP box1.protohackers.com.54446 > vps-6be738f9.vps.ovh.net.8080: UDP, length 17
E..-4s@...Sn..q|9.K$......Z./ack/489050934/6/
--
E..-..@.@...9.K$..q|.......	/ack/272876487/0/
21:09:23.587144 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43905: UDP, length 18
E.....@.@...9.K$..q|.......
/ack/1879912549/0/
21:09:23.684790 IP box1.protohackers.com.43905 > vps-6be738f9.vps.ovh.net.8080: UDP, length 42
E..F7y@...PO..q|9.K$.....2../data/836425705/0/of prisoners about hypn/
21:09:23.685176 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43905: UDP, length 18
E....7@.@...9.K$..q|.......
/ack/836425705/23/
21:09:23.784708 IP box1.protohackers.com.43905 > vps-6be738f9.vps.ovh.net.8080: UDP, length 233
E...7.@...O...q|9.K$......../data/836425705/23/otic PROTOHACKERS
the the
bluebell is come bluebell to giant something something favicon to
jackdaws giant aid
for for good something love quartz time the about the my to casino the favicon royale men
of good gian/
21:09:23.785086 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43905: UDP, length 19
E../.f@.@..x9.K$..q|......../ack/836425705/236/
21:09:23.785136 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43905: UDP, length 60
E..X.g@.@..N9.K$..q|.....D.4/data/836425705/0/SREKCAHOTORP citonpyh tuoba srenosirp fo
reading from file validation-3.pcap, link-type EN10MB (Ethernet), snapshot length 262144
tcpdump: Unable to write output: Broken pipe

   352→    async def process_new_data(self, session: Session, data: str):
   353→        self.log(f"PROCESS: Adding {repr(data)} to buffer for session {session.session_id}")
   354→        session.buffer += data
   355→        
   356→        while '\n' in session.buffer:
   357→            line, session.buffer = session.buffer.split('\n', 1)
   358→            reversed_line = line[::-1]
   359→            self.log(f"PROCESS: Reversing line {repr(line)} -> {repr(reversed_line)} for session {session.session_id}")
   360→            
   361→            # Send reversed line back (with newline)
   362→            response = reversed_line + '\n'
   363→            await self.send_data_chunked(session, response)
   364→    
   365→    async def retransmit_message(self, session_id: int, pos: int, msg: str):
   366→        """Handle retransmission of a single message"""

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

   323→    async def send_data_chunked(self, session: Session, data: str):
   324→        """Send data in chunks to avoid packets over 1000 bytes"""
   325→        max_data_size = 900  # Conservative limit to account for protocol overhead
   326→        
   327→        pos = 0
   328→        while pos < len(data):
   329→            chunk = data[pos:pos + max_data_size]
   330→            escaped_chunk = self.escape_data(chunk)
   331→            
   332→            # Store outgoing data
   333→            session.sent_data[session.sent_length] = chunk
   334→            msg = f'/data/{session.session_id}/{session.sent_length}/{escaped_chunk}/'
   335→            
   336→            # Check if message would be too large
   337→            if len(msg.encode('ascii')) >= 1000:
   338→                # Reduce chunk size and try again
   339→                max_data_size = max_data_size // 2
   340→                continue
   341→            
   342→            self.log(f"PROCESS: Sending chunk to session {session.session_id}: {len(chunk)} bytes at pos {session.sent_length}")
   343→            await self.send_message(session.addr, msg)
   344→            
   345→            # Start retransmission task for this message
   346→            task = asyncio.create_task(self.retransmit_message(session.session_id, session.sent_length, msg))
   347→            session.pending_retransmits[session.sent_length] = (msg, time.time(), 0, task)
   348→            
   349→            pos += len(chunk)
   350→            session.sent_length += len(chunk)
   351→
   352→    async def process_new_data(self, session: Session, data: str):

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

test_very_long_line_bug (test_long_lines.TestLongLines.test_very_long_line_bug)
Test that reproduces the long line bug - infinite loop in send_data_chunked ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 39178). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.004s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 46, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.004s] [Task-3] KEEPALIVE:   Session 12345: age=0.1s, recv=36000, sent=0, pending=0
[  10.009s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 120, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[  10.010s] [Task-3] KEEPALIVE:   Session 12345: age=3.3s, recv=50001, sent=50001, pending=0
FAIL
[  11.867s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[  11.867s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=5.1s)

======================================================================
FAIL: test_very_long_line_bug (test_long_lines.TestLongLines.test_very_long_line_bug)
Test that reproduces the long line bug - infinite loop in send_data_chunked
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_long_lines.py", line 151, in test_very_long_line_bug
    self.fail(f"Server appears to be stuck in infinite loop - only sent {len(total_response_data)} of {expected_length} bytes")
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: Server appears to be stuck in infinite loop - only sent 0 of 50001 bytes

----------------------------------------------------------------------
Ran 1 test in 11.868s

FAILED (failures=1)

Sending long line: 50001 bytes
Received ack: /ack/12345/800/
Received ack: /ack/12345/1600/
Received ack: /ack/12345/2400/
Received ack: /ack/12345/3200/
Received ack: /ack/12345/4000/
Received ack: /ack/12345/4800/
Received ack: /ack/12345/5600/
Received ack: /ack/12345/6400/
Received ack: /ack/12345/7200/
Received ack: /ack/12345/8000/
Received ack: /ack/12345/8800/
Received ack: /ack/12345/9600/
Received ack: /ack/12345/10400/
Received ack: /ack/12345/11200/
Received ack: /ack/12345/12000/
Received ack: /ack/12345/12800/
Received ack: /ack/12345/13600/
Received ack: /ack/12345/14400/
Received ack: /ack/12345/15200/
Received ack: /ack/12345/16000/
Received ack: /ack/12345/16800/
Received ack: /ack/12345/17600/
Received ack: /ack/12345/18400/
Received ack: /ack/12345/19200/
Received ack: /ack/12345/20000/
Received ack: /ack/12345/20800/
Received ack: /ack/12345/21600/
Received ack: /ack/12345/22400/
Received ack: /ack/12345/23200/
Received ack: /ack/12345/24000/
Received ack: /ack/12345/24800/
Received ack: /ack/12345/25600/
Received ack: /ack/12345/26400/
Received ack: /ack/12345/27200/
Received ack: /ack/12345/28000/
Received ack: /ack/12345/28800/
Received ack: /ack/12345/29600/
Received ack: /ack/12345/30400/
Received ack: /ack/12345/31200/
Received ack: /ack/12345/32000/
Received ack: /ack/12345/32800/
Received ack: /ack/12345/33600/
Received ack: /ack/12345/34400/
Received ack: /ack/12345/35200/
Received ack: /ack/12345/36000/
Received ack: /ack/12345/36800/
Received ack: /ack/12345/37600/
Received ack: /ack/12345/38400/
Received ack: /ack/12345/39200/
Received ack: /ack/12345/40000/
Received ack: /ack/12345/40800/
Received ack: /ack/12345/41600/
Received ack: /ack/12345/42400/
Received ack: /ack/12345/43200/
Received ack: /ack/12345/44000/
Received ack: /ack/12345/44800/
Received ack: /ack/12345/45600/
Received ack: /ack/12345/46400/
Received ack: /ack/12345/47200/
Received ack: /ack/12345/48000/
Received ack: /ack/12345/48800/
Received ack: /ack/12345/49600/
Received ack: /ack/12345/50001/
Received data response: 915 bytes
Received data response: 917 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 520 bytes
Sent complete long line, waiting for response...
Total response data length: 0
Expected response length: 50001
BUG REPRODUCED: Only received 0 of 50001 expected bytes

The file /home/smite/dev/protohackers/7-line-reversal/server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   319→            # Missing data or out of order, send duplicate ack
   320→            self.log(f"DATA: Out of order data for session {session_id}, sending duplicate ack {session.last_ack_sent}")
   321→            await self.send_message(addr, f'/ack/{session_id}/{session.last_ack_sent}/')
   322→    
   323→    async def send_data_chunked(self, session: Session, data: str):
   324→        """Send data in chunks to avoid packets over 1000 bytes"""
   325→        max_data_size = 900  # Conservative limit to account for protocol overhead
   326→        
   327→        pos = 0
   328→        while pos < len(data):
   329→            # Calculate chunk size for this iteration
   330→            chunk_size = min(max_data_size, len(data) - pos)
   331→            chunk = data[pos:pos + chunk_size]
   332→            escaped_chunk = self.escape_data(chunk)
   333→            
   334→            # Store outgoing data
   335→            session.sent_data[session.sent_length] = chunk
   336→            msg = f'/data/{session.session_id}/{session.sent_length}/{escaped_chunk}/'
   337→            
   338→            # Check if message would be too large
   339→            if len(msg.encode('ascii')) >= 1000:
   340→                # Reduce chunk size and try again with the same position
   341→                max_data_size = max_data_size // 2
   342→                if max_data_size < 1:
   343→                    # Safety check - if we can't fit even 1 character, something is very wrong
   344→                    self.log(f"ERROR: Cannot fit any data in packet for session {session.session_id}")
   345→                    break
   346→                continue  # Try again with smaller chunk size
   347→            
   348→            self.log(f"PROCESS: Sending chunk to session {session.session_id}: {len(chunk)} bytes at pos {session.sent_length}")
   349→            await self.send_message(session.addr, msg)
   350→            
   351→            # Start retransmission task for this message
   352→            task = asyncio.create_task(self.retransmit_message(session.session_id, session.sent_length, msg))
   353→            session.pending_retransmits[session.sent_length] = (msg, time.time(), 0, task)
   354→            
   355→            # Only advance position and sent_length after successfully sending
   356→            pos += len(chunk)
   357→            session.sent_length += len(chunk)
   358→            
   359→            # Reset max_data_size for next chunk (in case it was reduced)
   360→            max_data_size = min(900, max_data_size * 2)  # Gradually increase back up
   361→
   362→    async def process_new_data(self, session: Session, data: str):
   363→        self.log(f"PROCESS: Adding {repr(data)} to buffer for session {session.session_id}")
   364→        session.buffer += data

/home/smite/dev/protohackers/7-line-reversal/server.py:220: SyntaxWarning: invalid escape sequence '\/'
  """Check if data contains unescaped forward slashes (which should be escaped as \/)"""
test_very_long_line_bug (test_long_lines.TestLongLines.test_very_long_line_bug)
Test that reproduces the long line bug - infinite loop in send_data_chunked ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 41341). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.005s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 46, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.005s] [Task-3] KEEPALIVE:   Session 12345: age=0.1s, recv=36000, sent=0, pending=0
[  10.010s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 120, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[  10.010s] [Task-3] KEEPALIVE:   Session 12345: age=3.2s, recv=50001, sent=50001, pending=0
FAIL
[  11.871s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[  11.871s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=5.1s)

======================================================================
FAIL: test_very_long_line_bug (test_long_lines.TestLongLines.test_very_long_line_bug)
Test that reproduces the long line bug - infinite loop in send_data_chunked
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_long_lines.py", line 151, in test_very_long_line_bug
    self.fail(f"Server appears to be stuck in infinite loop - only sent {len(total_response_data)} of {expected_length} bytes")
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: Server appears to be stuck in infinite loop - only sent 0 of 50001 bytes

----------------------------------------------------------------------
Ran 1 test in 11.872s

FAILED (failures=1)

Sending long line: 50001 bytes
Received ack: /ack/12345/800/
Received ack: /ack/12345/1600/
Received ack: /ack/12345/2400/
Received ack: /ack/12345/3200/
Received ack: /ack/12345/4000/
Received ack: /ack/12345/4800/
Received ack: /ack/12345/5600/
Received ack: /ack/12345/6400/
Received ack: /ack/12345/7200/
Received ack: /ack/12345/8000/
Received ack: /ack/12345/8800/
Received ack: /ack/12345/9600/
Received ack: /ack/12345/10400/
Received ack: /ack/12345/11200/
Received ack: /ack/12345/12000/
Received ack: /ack/12345/12800/
Received ack: /ack/12345/13600/
Received ack: /ack/12345/14400/
Received ack: /ack/12345/15200/
Received ack: /ack/12345/16000/
Received ack: /ack/12345/16800/
Received ack: /ack/12345/17600/
Received ack: /ack/12345/18400/
Received ack: /ack/12345/19200/
Received ack: /ack/12345/20000/
Received ack: /ack/12345/20800/
Received ack: /ack/12345/21600/
Received ack: /ack/12345/22400/
Received ack: /ack/12345/23200/
Received ack: /ack/12345/24000/
Received ack: /ack/12345/24800/
Received ack: /ack/12345/25600/
Received ack: /ack/12345/26400/
Received ack: /ack/12345/27200/
Received ack: /ack/12345/28000/
Received ack: /ack/12345/28800/
Received ack: /ack/12345/29600/
Received ack: /ack/12345/30400/
Received ack: /ack/12345/31200/
Received ack: /ack/12345/32000/
Received ack: /ack/12345/32800/
Received ack: /ack/12345/33600/
Received ack: /ack/12345/34400/
Received ack: /ack/12345/35200/
Received ack: /ack/12345/36000/
Received ack: /ack/12345/36800/
Received ack: /ack/12345/37600/
Received ack: /ack/12345/38400/
Received ack: /ack/12345/39200/
Received ack: /ack/12345/40000/
Received ack: /ack/12345/40800/
Received ack: /ack/12345/41600/
Received ack: /ack/12345/42400/
Received ack: /ack/12345/43200/
Received ack: /ack/12345/44000/
Received ack: /ack/12345/44800/
Received ack: /ack/12345/45600/
Received ack: /ack/12345/46400/
Received ack: /ack/12345/47200/
Received ack: /ack/12345/48000/
Received ack: /ack/12345/48800/
Received ack: /ack/12345/49600/
Received ack: /ack/12345/50001/
Received data response: 915 bytes
Received data response: 917 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 520 bytes
Sent complete long line, waiting for response...
Total response data length: 0
Expected response length: 50001
BUG REPRODUCED: Only received 0 of 50001 expected bytes

The file /home/smite/dev/protohackers/7-line-reversal/test_long_lines.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   115→            pos += len(chunk)
   116→        
   117→        print(f"Sent complete long line, waiting for response...")
   118→        
   119→        # Parse the data responses we already received
   120→        total_response_data = ""
   121→        for response in responses_received:
   122→            parts = response.split('/')
   123→            if len(parts) >= 4:
   124→                resp_data = '/'.join(parts[4:-1])
   125→                unescaped_data = resp_data.replace(r'\/', '/').replace(r'\\', '\\')
   126→                total_response_data += unescaped_data
   127→                
   128→                # Send ack
   129→                resp_pos = int(parts[3])
   130→                ack_pos = resp_pos + len(unescaped_data)
   131→                self.send_message(f'/ack/12345/{ack_pos}/')
   132→        
   133→        # Wait for any additional server responses
   134→        start_time = time.time()
   135→        
   136→        while time.time() - start_time < 3.0:  # 3 second timeout
   137→            response = self.receive_message(timeout=0.5)
   138→            if response and response.startswith('/data/12345/'):
   139→                responses_received.append(response)
   140→                print(f"Received additional data response: {len(response)} bytes")
   141→                
   142→                # Parse and accumulate the data
   143→                parts = response.split('/')
   144→                if len(parts) >= 4:
   145→                    resp_data = '/'.join(parts[4:-1])
   146→                    unescaped_data = resp_data.replace(r'\/', '/').replace(r'\\', '\\')
   147→                    total_response_data += unescaped_data
   148→                    
   149→                    # Send ack
   150→                    resp_pos = int(parts[3])
   151→                    ack_pos = resp_pos + len(unescaped_data)
   152→                    self.send_message(f'/ack/12345/{ack_pos}/')
   153→        
   154→        print(f"Total response data length: {len(total_response_data)}")
   155→        print(f"Expected response length: {len(long_line) + 1}")  # +1 for newline
   156→        

Sending long line: 50001 bytes
Received ack: /ack/12345/800/
Received ack: /ack/12345/1600/
Received ack: /ack/12345/2400/
Received ack: /ack/12345/3200/
Received ack: /ack/12345/4000/
Received ack: /ack/12345/4800/
Received ack: /ack/12345/5600/
Received ack: /ack/12345/6400/
Received ack: /ack/12345/7200/
Received ack: /ack/12345/8000/
Received ack: /ack/12345/8800/
Received ack: /ack/12345/9600/
Received ack: /ack/12345/10400/
Received ack: /ack/12345/11200/
Received ack: /ack/12345/12000/
Received ack: /ack/12345/12800/
Received ack: /ack/12345/13600/
Received ack: /ack/12345/14400/
Received ack: /ack/12345/15200/
Received ack: /ack/12345/16000/
Received ack: /ack/12345/16800/
Received ack: /ack/12345/17600/
Received ack: /ack/12345/18400/
Received ack: /ack/12345/19200/
Received ack: /ack/12345/20000/
Received ack: /ack/12345/20800/
Received ack: /ack/12345/21600/
Received ack: /ack/12345/22400/
Received ack: /ack/12345/23200/
Received ack: /ack/12345/24000/
Received ack: /ack/12345/24800/
Received ack: /ack/12345/25600/
Received ack: /ack/12345/26400/
Received ack: /ack/12345/27200/
Received ack: /ack/12345/28000/
Received ack: /ack/12345/28800/
Received ack: /ack/12345/29600/
Received ack: /ack/12345/30400/
Received ack: /ack/12345/31200/
Received ack: /ack/12345/32000/
Received ack: /ack/12345/32800/
Received ack: /ack/12345/33600/
Received ack: /ack/12345/34400/
Received ack: /ack/12345/35200/
Received ack: /ack/12345/36000/
Received ack: /ack/12345/36800/
Received ack: /ack/12345/37600/
Received ack: /ack/12345/38400/
Received ack: /ack/12345/39200/
Received ack: /ack/12345/40000/
Received ack: /ack/12345/40800/
Received ack: /ack/12345/41600/
Received ack: /ack/12345/42400/
Received ack: /ack/12345/43200/
Received ack: /ack/12345/44000/
Received ack: /ack/12345/44800/
Received ack: /ack/12345/45600/
Received ack: /ack/12345/46400/
Received ack: /ack/12345/47200/
Received ack: /ack/12345/48000/
Received ack: /ack/12345/48800/
Received ack: /ack/12345/49600/
Received ack: /ack/12345/50001/
Received data response: 915 bytes
Received data response: 917 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 520 bytes
Sent complete long line, waiting for response...
Total response data length: 50001
Expected response length: 50001
No bug detected - received appropriate amount of data
test_very_long_line_bug (test_long_lines.TestLongLines.test_very_long_line_bug)
Test that reproduces the long line bug - infinite loop in send_data_chunked ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 39902). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.005s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 46, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.005s] [Task-3] KEEPALIVE:   Session 12345: age=0.1s, recv=36000, sent=0, pending=0
[   9.870s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   9.870s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=3.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 9.872s

OK

The file /home/smite/dev/protohackers/7-line-reversal/test_long_lines.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   153→        
   154→        print(f"Total response data length: {len(total_response_data)}")
   155→        print(f"Expected response length: {len(long_line) + 1}")  # +1 for newline
   156→        
   157→        # The bug manifests as receiving much less data than expected
   158→        # Original: 50000 chars + newline = 50001 chars
   159→        # With bug: only a small portion gets sent
   160→        expected_length = len(long_line) + 1
   161→        if len(total_response_data) < expected_length * 0.5:
   162→            print(f"BUG REPRODUCED: Only received {len(total_response_data)} of {expected_length} expected bytes")
   163→            self.fail(f"Server appears to be stuck in infinite loop - only sent {len(total_response_data)} of {expected_length} bytes")
   164→        else:
   165→            print("No bug detected - received appropriate amount of data")
   166→            
   167→            # Verify the content is actually properly reversed
   168→            expected_response = long_line[::-1] + '\n'
   169→            if total_response_data == expected_response:
   170→                print("✓ Content verification: Line correctly reversed")
   171→            else:
   172→                print(f"✗ Content verification failed!")
   173→                print(f"Expected first 100 chars: {expected_response[:100]}")
   174→                print(f"Received first 100 chars: {total_response_data[:100]}")
   175→                print(f"Expected last 100 chars: {expected_response[-100:]}")
   176→                print(f"Received last 100 chars: {total_response_data[-100:]}")
   177→                self.fail("Content was not properly reversed")
   178→
   179→
   180→if __name__ == '__main__':
   181→    unittest.main()

Sending long line: 50001 bytes
Received ack: /ack/12345/800/
Received ack: /ack/12345/1600/
Received ack: /ack/12345/2400/
Received ack: /ack/12345/3200/
Received ack: /ack/12345/4000/
Received ack: /ack/12345/4800/
Received ack: /ack/12345/5600/
Received ack: /ack/12345/6400/
Received ack: /ack/12345/7200/
Received ack: /ack/12345/8000/
Received ack: /ack/12345/8800/
Received ack: /ack/12345/9600/
Received ack: /ack/12345/10400/
Received ack: /ack/12345/11200/
Received ack: /ack/12345/12000/
Received ack: /ack/12345/12800/
Received ack: /ack/12345/13600/
Received ack: /ack/12345/14400/
Received ack: /ack/12345/15200/
Received ack: /ack/12345/16000/
Received ack: /ack/12345/16800/
Received ack: /ack/12345/17600/
Received ack: /ack/12345/18400/
Received ack: /ack/12345/19200/
Received ack: /ack/12345/20000/
Received ack: /ack/12345/20800/
Received ack: /ack/12345/21600/
Received ack: /ack/12345/22400/
Received ack: /ack/12345/23200/
Received ack: /ack/12345/24000/
Received ack: /ack/12345/24800/
Received ack: /ack/12345/25600/
Received ack: /ack/12345/26400/
Received ack: /ack/12345/27200/
Received ack: /ack/12345/28000/
Received ack: /ack/12345/28800/
Received ack: /ack/12345/29600/
Received ack: /ack/12345/30400/
Received ack: /ack/12345/31200/
Received ack: /ack/12345/32000/
Received ack: /ack/12345/32800/
Received ack: /ack/12345/33600/
Received ack: /ack/12345/34400/
Received ack: /ack/12345/35200/
Received ack: /ack/12345/36000/
Received ack: /ack/12345/36800/
Received ack: /ack/12345/37600/
Received ack: /ack/12345/38400/
Received ack: /ack/12345/39200/
Received ack: /ack/12345/40000/
Received ack: /ack/12345/40800/
Received ack: /ack/12345/41600/
Received ack: /ack/12345/42400/
Received ack: /ack/12345/43200/
Received ack: /ack/12345/44000/
Received ack: /ack/12345/44800/
Received ack: /ack/12345/45600/
Received ack: /ack/12345/46400/
Received ack: /ack/12345/47200/
Received ack: /ack/12345/48000/
Received ack: /ack/12345/48800/
Received ack: /ack/12345/49600/
Received ack: /ack/12345/50001/
Received data response: 915 bytes
Received data response: 917 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 520 bytes
Sent complete long line, waiting for response...
Total response data length: 50001
Expected response length: 50001
No bug detected - received appropriate amount of data
✓ Content verification: Line correctly reversed
test_very_long_line_bug (test_long_lines.TestLongLines.test_very_long_line_bug)
Test that reproduces the long line bug - infinite loop in send_data_chunked ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 47881). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.005s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 46, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.005s] [Task-3] KEEPALIVE:   Session 12345: age=0.1s, recv=36000, sent=0, pending=0
[   9.863s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   9.863s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=3.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 9.864s

OK

test_simple_line_reversal (test_server.TestLRCPServer.test_simple_line_reversal) ... ERROR

======================================================================
ERROR: test_simple_line_reversal (test_server.TestLRCPServer.test_simple_line_reversal)
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_server.py", line 14, in setUp
    self.server_addr = self.server.socket.getsockname()
                       ^^^^^^^^^^^^^^^^^^
AttributeError: 'AsyncLRCPServer' object has no attribute 'socket'

----------------------------------------------------------------------
Ran 1 test in 0.001s

FAILED (errors=1)

Created test data: 41463 bytes, 813 lines
Sent 60 packets, total 41463 bytes
Received 813 response packets
Expected 813 responses
Successfully verified 100 proper line reversals
Successfully verified large data transfer with proper packet size limits and content reversal
test_40kb_data_transfer_with_packet_validation (test_server.TestLargePackets.test_40kb_data_transfer_with_packet_validation)
Test transferring 40KB of data and validate packet sizes are under 1000 bytes ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 49849). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.004s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 663, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.004s] [Task-3] KEEPALIVE:   Session 12345: age=0.0s, recv=31500, sent=31467, pending=0
[   6.647s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   6.647s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.1s)
ok

----------------------------------------------------------------------
Ran 1 test in 6.648s

OK

test_medium_line (test_basic_functionality.TestBasicFunctionality.test_medium_line)
Test medium-sized line to ensure chunking works correctly ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 58378). Total sessions: 1 (created=1, closed=0, expired=0)
FAIL
[   2.506s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   2.506s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=2.0s)
test_multiple_lines (test_basic_functionality.TestBasicFunctionality.test_multiple_lines)
Test multiple line reversal ... [   0.000s] [Task-6] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-9] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 55090). Total sessions: 1 (created=1, closed=0, expired=0)
[   0.502s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   0.502s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.0s)
ok
test_simple_line_reversal (test_basic_functionality.TestBasicFunctionality.test_simple_line_reversal)
Test basic line reversal functionality ... [   0.000s] [Task-18] KEEPALIVE: Server started and ready to receive packets
[   0.500s] [Task-21] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 47256). Total sessions: 1 (created=1, closed=0, expired=0)
[   0.501s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   0.501s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.0s)
ok

======================================================================
FAIL: test_medium_line (test_basic_functionality.TestBasicFunctionality.test_medium_line)
Test medium-sized line to ensure chunking works correctly
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_basic_functionality.py", line 141, in test_medium_line
    self.assertEqual(ack_response, f'/ack/12345/{len(medium_line)}/')
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: None != '/ack/12345/2001/'

----------------------------------------------------------------------
Ran 3 tests in 3.513s

FAILED (failures=1)
Task was destroyed but it is pending!
task: <Task pending name='Task-14' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:375> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-17' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:375> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-23' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:375> wait_for=<Future pending cb=[Task.task_wakeup()]>>

✓ Multiple line reversal working correctly
✓ Simple line reversal working correctly

-rw-r--r-- 1 tcpdump tcpdump 3271296 Aug 20 13:23 validation-1.pcap
-rw-r--r-- 1 tcpdump tcpdump 2961491 Aug 20 13:32 validation-2.pcap
-rw-r--r-- 1 tcpdump tcpdump 2829372 Aug 20 21:11 validation-3.pcap
-rw-r--r-- 1 tcpdump tcpdump 4142784 Aug 20 21:24 validation-4.pcap

E..-..@.@.[_9.K$..q|.......	/ack/307851424/0/
E..5..@....6..q|9.K$.....!../data/307851424/0/hello
E..5..@....5..q|9.K$.....!../data/307851424/0/hello
E..-..@.@.[U9.K$..q|.......	/ack/307851424/6/
E..5..@.@.[L9.K$..q|.....!../data/307851424/0/olleh
E..-..@.@.[S9.K$..q|.......	/ack/307851424/6/
E..-..@....;..q|9.K$......d$/ack/307851424/6/
/ack/1424468381/0/
E..-'.@.@.M.9.K$..q|.......	/ack/526708170/0/
E..-'.@.@.M.9.K$..q|.......	/ack/937800644/0/
/ack/1164183945/0/
/ack/1365684306/0/
/ack/1487943282/0/
/ack/1081476838/0/
/ack/1247867160/0/
/ack/1707468479/0/
/ack/1789789595/0/
E..V.n@....I..q|9.K$.....B../data/937800644/0/now intrusion now nasa giant royale is /
/ack/937800644/39/
E....z@.......q|9.K$......../data/1789789595/0/quartz quartz integral good the party giant casino of giant party nasa jackdaws casino about of intrusion giant about
reading from file validation-4.pcap, link-type EN10MB (Ethernet), snapshot length 262144
tcpdump: Unable to write output: Broken pipe

   275→        # FIXME: is empty data malformed? 
   276→        if not data:
   277→            self.keepalive_log(f"DATA: Empty data received for session {session_id}, ignoring")
   278→            return
   279→
   280→        # Unescape the data
   281→        unescaped_data = self.unescape_data(data)
   282→        
   283→        # Check if this is new data or a duplicate
   284→        is_new_data = pos not in session.received_data
   285→        
   286→        # Store the data if we don't already have it
   287→        if is_new_data:
   288→            session.received_data[pos] = unescaped_data
   289→        
   290→        # Reconstruct continuous data from position 0
   291→        continuous_data = ""
   292→
   293→        previous_next_pos = -1
   294→        next_pos = 0
   295→        while next_pos in session.received_data:
   296→            continuous_data += session.received_data[next_pos]
   297→            next_pos += len(session.received_data[next_pos])
   298→            if next_pos == previous_next_pos:
   299→                # show received data
   300→                self.keepalive_log(f"DATA: Stuck in loop while reconstructing continuous data for session {session_id} at pos {next_pos}, data: {data}, unescaped data: {unescaped_data}")
   301→                break
   302→            previous_next_pos = next_pos
   303→        
   304→        # Check if we have all data up to the current position

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

   304→        # Check if we have all data up to the current position
   305→        if pos == len(continuous_data) - len(unescaped_data):
   306→            # We have everything up to this position including current data
   307→            session.received_length = len(continuous_data)
   308→            await self.send_message(addr, f'/ack/{session_id}/{session.received_length}/')
   309→            session.last_ack_sent = session.received_length
   310→            self.log(f"DATA: Sent ack {session.received_length} to session {session_id}")
   311→            
   312→            # Process new data for line reversal ONLY if this is actually new data
   313→            if is_new_data:
   314→                self.log(f"DATA: Processing new data for session {session_id}")
   315→                await self.process_new_data(session, unescaped_data)
   316→            else:
   317→                self.log(f"DATA: Duplicate data for session {session_id}, not processing")
   318→        else:
   319→            # Missing data or out of order, send duplicate ack
   320→            self.log(f"DATA: Out of order data for session {session_id}, sending duplicate ack {session.last_ack_sent}")
   321→            await self.send_message(addr, f'/ack/{session_id}/{session.last_ack_sent}/')
   322→    
   323→    async def send_data_chunked(self, session: Session, data: str):
   324→        """Send data in chunks to avoid packets over 1000 bytes"""
   325→        max_data_size = 900  # Conservative limit to account for protocol overhead
   326→        
   327→        pos = 0
   328→        while pos < len(data):

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

test_multi_chunk_line_processing_bug (test_position_bug.TestPositionBug.test_multi_chunk_line_processing_bug)
Test that reproduces the position bug where only first chunk is processed ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 49917). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.004s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 7, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.004s] [Task-3] KEEPALIVE:   Session 12345: age=4.5s, recv=2001, sent=2001, pending=0
FAIL
[   5.511s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   5.511s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=5.0s)

======================================================================
FAIL: test_multi_chunk_line_processing_bug (test_position_bug.TestPositionBug.test_multi_chunk_line_processing_bug)
Test that reproduces the position bug where only first chunk is processed
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_position_bug.py", line 156, in test_multi_chunk_line_processing_bug
    self.fail("Content was not properly reversed")
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: Content was not properly reversed

----------------------------------------------------------------------
Ran 1 test in 5.512s

FAILED (failures=1)

Sending line requiring multiple chunks: 2001 bytes
Sending chunk 1: pos=0, length=800
Expected ack: /ack/12345/800/
Received ack: /ack/12345/800/
Sending chunk 2: pos=800, length=800
Expected ack: /ack/12345/1600/
Received ack: /ack/12345/1600/
Sending chunk 3: pos=1600, length=401
Expected ack: /ack/12345/2001/
Received ack: /ack/12345/2001/
Sent 3 chunks, total 2001 bytes
Waiting for response data...
Received data response: 915 bytes
Received data response: 917 bytes
Received data response: 219 bytes
Total response data length: 2001
Expected response length: 2001
❌ Content mismatch - line not properly reversed

   362→    async def process_new_data(self, session: Session, data: str):
   363→        self.log(f"PROCESS: Adding {repr(data)} to buffer for session {session.session_id}")
   364→        session.buffer += data
   365→        
   366→        while '\n' in session.buffer:
   367→            line, session.buffer = session.buffer.split('\n', 1)
   368→            reversed_line = line[::-1]
   369→            self.log(f"PROCESS: Reversing line {repr(line)} -> {repr(reversed_line)} for session {session.session_id}")
   370→            
   371→            # Send reversed line back (with newline)
   372→            response = reversed_line + '\n'
   373→            await self.send_data_chunked(session, response)
   374→    
   375→    async def retransmit_message(self, session_id: int, pos: int, msg: str):
   376→        """Handle retransmission of a single message"""

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

The file /home/smite/dev/protohackers/7-line-reversal/server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   300→                self.keepalive_log(f"DATA: Stuck in loop while reconstructing continuous data for session {session_id} at pos {next_pos}, data: {data}, unescaped data: {unescaped_data}")
   301→                break
   302→            previous_next_pos = next_pos
   303→        
   304→        # Check if we have all data up to the current position
   305→        if pos + len(unescaped_data) == len(continuous_data):
   306→            # We have everything up to this position including current data
   307→            session.received_length = len(continuous_data)
   308→            await self.send_message(addr, f'/ack/{session_id}/{session.received_length}/')
   309→            session.last_ack_sent = session.received_length
   310→            self.log(f"DATA: Sent ack {session.received_length} to session {session_id}")
   311→            
   312→            # Process new data for line reversal ONLY if this is actually new data
   313→            if is_new_data:
   314→                self.log(f"DATA: Processing new data for session {session_id}")
   315→                await self.process_new_data(session, unescaped_data)
   316→            else:
   317→                self.log(f"DATA: Duplicate data for session {session_id}, not processing")
   318→        else:
   319→            # Missing data or out of order, send duplicate ack
   320→            self.log(f"DATA: Out of order data for session {session_id}, sending duplicate ack {session.last_ack_sent}")
   321→            await self.send_message(addr, f'/ack/{session_id}/{session.last_ack_sent}/')

/home/smite/dev/protohackers/7-line-reversal/server.py:220: SyntaxWarning: invalid escape sequence '\/'
  """Check if data contains unescaped forward slashes (which should be escaped as \/)"""
test_multi_chunk_line_processing_bug (test_position_bug.TestPositionBug.test_multi_chunk_line_processing_bug)
Test that reproduces the position bug where only first chunk is processed ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 40053). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.005s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 7, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.005s] [Task-3] KEEPALIVE:   Session 12345: age=4.5s, recv=2001, sent=2001, pending=0
FAIL
[   5.509s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   5.509s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=5.0s)

======================================================================
FAIL: test_multi_chunk_line_processing_bug (test_position_bug.TestPositionBug.test_multi_chunk_line_processing_bug)
Test that reproduces the position bug where only first chunk is processed
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_position_bug.py", line 156, in test_multi_chunk_line_processing_bug
    self.fail("Content was not properly reversed")
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: Content was not properly reversed

----------------------------------------------------------------------
Ran 1 test in 5.510s

FAILED (failures=1)

Sending line requiring multiple chunks: 2001 bytes
Sending chunk 1: pos=0, length=800
Expected ack: /ack/12345/800/
Received ack: /ack/12345/800/
Sending chunk 2: pos=800, length=800
Expected ack: /ack/12345/1600/
Received ack: /ack/12345/1600/
Sending chunk 3: pos=1600, length=401
Expected ack: /ack/12345/2001/
Received ack: /ack/12345/2001/
Sent 3 chunks, total 2001 bytes
Waiting for response data...
Received data response: 915 bytes
Received data response: 917 bytes
Received data response: 219 bytes
Total response data length: 2001
Expected response length: 2001
❌ Content mismatch - line not properly reversed

The file /home/smite/dev/protohackers/7-line-reversal/test_position_bug.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   146→        elif len(total_response_data) < total_length:
   147→            print(f"❌ PARTIAL BUG: Only {len(total_response_data)} of {total_length} bytes returned")
   148→            self.fail(f"Server only returned partial data: {len(total_response_data)}/{total_length}")
   149→        else:
   150→            # Verify content is correctly reversed
   151→            expected_response = long_line[::-1]
   152→            if total_response_data == expected_response:
   153→                print("✅ SUCCESS: Multi-chunk line correctly processed and reversed")
   154→            else:
   155→                print("❌ Content mismatch - line not properly reversed")
   156→                print(f"Expected first 100 chars: {expected_response[:100]}")
   157→                print(f"Received first 100 chars: {total_response_data[:100]}")
   158→                print(f"Expected last 100 chars:  {expected_response[-100:]}")
   159→                print(f"Received last 100 chars:  {total_response_data[-100:]}")
   160→                
   161→                # Check if the issue is ordering
   162→                if sorted(total_response_data) == sorted(expected_response):
   163→                    print("🔍 Content has same characters but different order (chunking issue)")
   164→                else:
   165→                    print("🔍 Content has different characters (processing issue)")
   166→                    
   167→                self.fail("Content was not properly reversed")
   168→
   169→
   170→if __name__ == '__main__':
   171→    unittest.main()

test_multi_chunk_line_processing_bug (test_position_bug.TestPositionBug.test_multi_chunk_line_processing_bug)
Test that reproduces the position bug where only first chunk is processed ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 60440). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.005s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 7, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.005s] [Task-3] KEEPALIVE:   Session 12345: age=4.5s, recv=2001, sent=2001, pending=0
FAIL
[   5.509s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   5.509s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=5.0s)

======================================================================
FAIL: test_multi_chunk_line_processing_bug (test_position_bug.TestPositionBug.test_multi_chunk_line_processing_bug)
Test that reproduces the position bug where only first chunk is processed
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_position_bug.py", line 167, in test_multi_chunk_line_processing_bug
    self.fail("Content was not properly reversed")
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: Content was not properly reversed

----------------------------------------------------------------------
Ran 1 test in 5.510s

FAILED (failures=1)

Sending line requiring multiple chunks: 2001 bytes
Sending chunk 1: pos=0, length=800
Expected ack: /ack/12345/800/
Received ack: /ack/12345/800/
Sending chunk 2: pos=800, length=800
Expected ack: /ack/12345/1600/
Received ack: /ack/12345/1600/
Sending chunk 3: pos=1600, length=401
Expected ack: /ack/12345/2001/
Received ack: /ack/12345/2001/
Sent 3 chunks, total 2001 bytes
Waiting for response data...
Received data response: 915 bytes
Received data response: 917 bytes
Received data response: 219 bytes
Total response data length: 2001
Expected response length: 2001
❌ Content mismatch - line not properly reversed
Expected first 100 chars: 
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
Received first 100 chars: BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
Expected last 100 chars:  BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
Received last 100 chars:  BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB

🔍 Content has same characters but different order (chunking issue)

   310→            self.log(f"DATA: Sent ack {session.received_length} to session {session_id}")
   311→            
   312→            # Process new data for line reversal ONLY if this is actually new data
   313→            if is_new_data:
   314→                self.log(f"DATA: Processing new data for session {session_id}")
   315→                await self.process_new_data(session, unescaped_data)
   316→            else:
   317→                self.log(f"DATA: Duplicate data for session {session_id}, not processing")
   318→        else:
   319→            # Missing data or out of order, send duplicate ack
   320→            self.log(f"DATA: Out of order data for session {session_id}, sending duplicate ack {session.last_ack_sent}")
   321→            await self.send_message(addr, f'/ack/{session_id}/{session.last_ack_sent}/')
   322→    
   323→    async def send_data_chunked(self, session: Session, data: str):
   324→        """Send data in chunks to avoid packets over 1000 bytes"""

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

The file /home/smite/dev/protohackers/7-line-reversal/server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   308→            await self.send_message(addr, f'/ack/{session_id}/{session.received_length}/')
   309→            session.last_ack_sent = session.received_length
   310→            self.log(f"DATA: Sent ack {session.received_length} to session {session_id}")
   311→            
   312→            # Process all continuous data for line reversal ONLY if this is actually new data
   313→            if is_new_data:
   314→                self.log(f"DATA: Processing continuous data for session {session_id}")
   315→                # Rebuild the session buffer from continuous data
   316→                session.buffer = continuous_data
   317→                await self.process_complete_lines(session)
   318→            else:
   319→                self.log(f"DATA: Duplicate data for session {session_id}, not processing")
   320→        else:
   321→            # Missing data or out of order, send duplicate ack
   322→            self.log(f"DATA: Out of order data for session {session_id}, sending duplicate ack {session.last_ack_sent}")
   323→            await self.send_message(addr, f'/ack/{session_id}/{session.last_ack_sent}/')

The file /home/smite/dev/protohackers/7-line-reversal/server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   360→            
   361→            # Reset max_data_size for next chunk (in case it was reduced)
   362→            max_data_size = min(900, max_data_size * 2)  # Gradually increase back up
   363→
   364→    async def process_complete_lines(self, session: Session):
   365→        """Process complete lines from the session buffer, avoiding reprocessing"""
   366→        self.log(f"PROCESS: Processing complete lines for session {session.session_id}, buffer length: {len(session.buffer)}")
   367→        
   368→        # Keep track of how much we've already processed to avoid reprocessing
   369→        if not hasattr(session, 'processed_buffer_length'):
   370→            session.processed_buffer_length = 0
   371→        
   372→        # Only process new data that we haven't processed before
   373→        unprocessed_data = session.buffer[session.processed_buffer_length:]
   374→        
   375→        # Find complete lines in the unprocessed data
   376→        lines_processed = 0
   377→        temp_buffer = unprocessed_data
   378→        
   379→        while '\n' in temp_buffer:
   380→            line, temp_buffer = temp_buffer.split('\n', 1)
   381→            
   382→            # Reconstruct the complete line by adding any remaining from previous processing
   383→            if lines_processed == 0 and session.processed_buffer_length > 0:
   384→                # First line might be continuation of previous incomplete line
   385→                # Find where the last incomplete line started
   386→                last_newline_pos = session.buffer.rfind('\n', 0, session.processed_buffer_length)
   387→                if last_newline_pos == -1:
   388→                    # No previous newline, so everything from start is part of this line
   389→                    complete_line = session.buffer[:session.processed_buffer_length + len(line)]
   390→                else:
   391→                    # Get the partial line after the last newline
   392→                    partial_line = session.buffer[last_newline_pos + 1:session.processed_buffer_length]
   393→                    complete_line = partial_line + line
   394→            else:
   395→                complete_line = line
   396→            
   397→            reversed_line = complete_line[::-1]
   398→            self.log(f"PROCESS: Reversing line {repr(complete_line)} -> {repr(reversed_line)} for session {session.session_id}")
   399→            
   400→            # Send reversed line back (with newline)
   401→            response = reversed_line + '\n'
   402→            await self.send_data_chunked(session, response)
   403→            
   404→            lines_processed += 1
   405→            # Update processed length to include this line + newline
   406→            session.processed_buffer_length += len(line) + 1
   407→        
   408→        self.log(f"PROCESS: Processed {lines_processed} complete lines for session {session.session_id}")
   409→
   410→    async def process_new_data(self, session: Session, data: str):
   411→        """Legacy function - now redirects to process_complete_lines"""
   412→        self.log(f"PROCESS: Adding {repr(data)} to buffer for session {session.session_id}")
   413→        session.buffer += data
   414→        await self.process_complete_lines(session)
   415→    
   416→    async def retransmit_message(self, session_id: int, pos: int, msg: str):
   417→        """Handle retransmission of a single message"""
   418→        try:

The file /home/smite/dev/protohackers/7-line-reversal/server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   308→            await self.send_message(addr, f'/ack/{session_id}/{session.received_length}/')
   309→            session.last_ack_sent = session.received_length
   310→            self.log(f"DATA: Sent ack {session.received_length} to session {session_id}")
   311→            
   312→            # Process all continuous data for line reversal ONLY if this is actually new data
   313→            if is_new_data:
   314→                self.log(f"DATA: Rebuilding buffer from continuous data for session {session_id}")
   315→                # Rebuild the session buffer from continuous data and process any new complete lines
   316→                old_buffer = session.buffer
   317→                session.buffer = continuous_data
   318→                await self.process_new_complete_lines(session, old_buffer)
   319→            else:
   320→                self.log(f"DATA: Duplicate data for session {session_id}, not processing")
   321→        else:
   322→            # Missing data or out of order, send duplicate ack
   323→            self.log(f"DATA: Out of order data for session {session_id}, sending duplicate ack {session.last_ack_sent}")
   324→            await self.send_message(addr, f'/ack/{session_id}/{session.last_ack_sent}/')

The file /home/smite/dev/protohackers/7-line-reversal/server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   361→            
   362→            # Reset max_data_size for next chunk (in case it was reduced)
   363→            max_data_size = min(900, max_data_size * 2)  # Gradually increase back up
   364→
   365→    async def process_new_complete_lines(self, session: Session, old_buffer: str):
   366→        """Process any new complete lines that weren't in the old buffer"""
   367→        self.log(f"PROCESS: Checking for new complete lines. Old buffer: {len(old_buffer)}, New buffer: {len(session.buffer)}")
   368→        
   369→        # Count complete lines in old buffer
   370→        old_lines = old_buffer.count('\n')
   371→        new_lines = session.buffer.count('\n')
   372→        
   373→        if new_lines > old_lines:
   374→            # We have new complete lines to process
   375→            self.log(f"PROCESS: Found {new_lines - old_lines} new complete lines")
   376→            
   377→            # Split buffer into lines
   378→            lines = session.buffer.split('\n')
   379→            
   380→            # Process only the new complete lines (skip the last element if it's not complete)
   381→            lines_to_process = lines[old_lines:new_lines]
   382→            
   383→            for line in lines_to_process:
   384→                reversed_line = line[::-1]
   385→                self.log(f"PROCESS: Reversing line {repr(line)} -> {repr(reversed_line)} for session {session.session_id}")
   386→                
   387→                # Send reversed line back (with newline)
   388→                response = reversed_line + '\n'
   389→                await self.send_data_chunked(session, response)
   390→        
   391→        # Update buffer to keep only the incomplete line at the end
   392→        if '\n' in session.buffer:
   393→            last_newline_pos = session.buffer.rfind('\n')
   394→            session.buffer = session.buffer[last_newline_pos + 1:]
   395→        
   396→        self.log(f"PROCESS: Buffer after processing: {repr(session.buffer)}")
   397→
   398→    async def process_new_data(self, session: Session, data: str):
   399→        """Legacy function - now redirects to process_new_complete_lines"""
   400→        self.log(f"PROCESS: Adding {repr(data)} to buffer for session {session.session_id}")
   401→        old_buffer = session.buffer
   402→        session.buffer += data
   403→        await self.process_new_complete_lines(session, old_buffer)
   404→    
   405→    async def retransmit_message(self, session_id: int, pos: int, msg: str):
   406→        """Handle retransmission of a single message"""
   407→        try:

/home/smite/dev/protohackers/7-line-reversal/server.py:220: SyntaxWarning: invalid escape sequence '\/'
  """Check if data contains unescaped forward slashes (which should be escaped as \/)"""
test_multi_chunk_line_processing_bug (test_position_bug.TestPositionBug.test_multi_chunk_line_processing_bug)
Test that reproduces the position bug where only first chunk is processed ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 48068). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.005s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 7, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.005s] [Task-3] KEEPALIVE:   Session 12345: age=4.5s, recv=2001, sent=2001, pending=0
FAIL
[   5.510s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   5.510s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=5.0s)

======================================================================
FAIL: test_multi_chunk_line_processing_bug (test_position_bug.TestPositionBug.test_multi_chunk_line_processing_bug)
Test that reproduces the position bug where only first chunk is processed
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_position_bug.py", line 167, in test_multi_chunk_line_processing_bug
    self.fail("Content was not properly reversed")
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: Content was not properly reversed

----------------------------------------------------------------------
Ran 1 test in 5.511s

FAILED (failures=1)

Sending line requiring multiple chunks: 2001 bytes
Sending chunk 1: pos=0, length=800
Expected ack: /ack/12345/800/
Received ack: /ack/12345/800/
Sending chunk 2: pos=800, length=800
Expected ack: /ack/12345/1600/
Received ack: /ack/12345/1600/
Sending chunk 3: pos=1600, length=401
Expected ack: /ack/12345/2001/
Received ack: /ack/12345/2001/
Sent 3 chunks, total 2001 bytes
Waiting for response data...
Received data response: 915 bytes
Received data response: 917 bytes
Received data response: 219 bytes
Total response data length: 2001
Expected response length: 2001
❌ Content mismatch - line not properly reversed
Expected first 100 chars: 
BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
Received first 100 chars: BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
Expected last 100 chars:  BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
Received last 100 chars:  BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB

🔍 Content has same characters but different order (chunking issue)

Sending long line: 50001 bytes
Received ack: /ack/12345/800/
Received ack: /ack/12345/1600/
Received ack: /ack/12345/2400/
Received ack: /ack/12345/3200/
Received ack: /ack/12345/4000/
Received ack: /ack/12345/4800/
Received ack: /ack/12345/5600/
Received ack: /ack/12345/6400/
Received ack: /ack/12345/7200/
Received ack: /ack/12345/8000/
Received ack: /ack/12345/8800/
Received ack: /ack/12345/9600/
Received ack: /ack/12345/10400/
Received ack: /ack/12345/11200/
Received ack: /ack/12345/12000/
Received ack: /ack/12345/12800/
Received ack: /ack/12345/13600/
Received ack: /ack/12345/14400/
Received ack: /ack/12345/15200/
Received ack: /ack/12345/16000/
Received ack: /ack/12345/16800/
Received ack: /ack/12345/17600/
Received ack: /ack/12345/18400/
Received ack: /ack/12345/19200/
Received ack: /ack/12345/20000/
Received ack: /ack/12345/20800/
Received ack: /ack/12345/21600/
Received ack: /ack/12345/22400/
Received ack: /ack/12345/23200/
Received ack: /ack/12345/24000/
Received ack: /ack/12345/24800/
Received ack: /ack/12345/25600/
Received ack: /ack/12345/26400/
Received ack: /ack/12345/27200/
Received ack: /ack/12345/28000/
Received ack: /ack/12345/28800/
Received ack: /ack/12345/29600/
Received ack: /ack/12345/30400/
Received ack: /ack/12345/31200/
Received ack: /ack/12345/32000/
Received ack: /ack/12345/32800/
Received ack: /ack/12345/33600/
Received ack: /ack/12345/34400/
Received ack: /ack/12345/35200/
Received ack: /ack/12345/36000/
Received ack: /ack/12345/36800/
Received ack: /ack/12345/37600/
Received ack: /ack/12345/38400/
Received ack: /ack/12345/39200/
Received ack: /ack/12345/40000/
Received ack: /ack/12345/40800/
Received ack: /ack/12345/41600/
Received ack: /ack/12345/42400/
Received ack: /ack/12345/43200/
Received ack: /ack/12345/44000/
Received ack: /ack/12345/44800/
Received ack: /ack/12345/45600/
Received ack: /ack/12345/46400/
Received ack: /ack/12345/47200/
Received ack: /ack/12345/48000/
Received ack: /ack/12345/48800/
Received ack: /ack/12345/49600/
Received ack: /ack/12345/50001/
Received data response: 915 bytes
Received data response: 917 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 520 bytes
Sent complete long line, waiting for response...
Total response data length: 50001
Expected response length: 50001
No bug detected - received appropriate amount of data
✓ Content verification: Line correctly reversed
test_very_long_line_bug (test_long_lines.TestLongLines.test_very_long_line_bug)
Test that reproduces the long line bug - infinite loop in send_data_chunked ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 33618). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.005s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 46, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.005s] [Task-3] KEEPALIVE:   Session 12345: age=0.1s, recv=36000, sent=0, pending=0
[   9.875s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   9.875s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=3.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 9.876s

OK

test_medium_line (test_basic_functionality.TestBasicFunctionality.test_medium_line)
Test medium-sized line to ensure chunking works correctly ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 50861). Total sessions: 1 (created=1, closed=0, expired=0)
FAIL
[   2.504s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   2.504s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=2.0s)
test_multiple_lines (test_basic_functionality.TestBasicFunctionality.test_multiple_lines)
Test multiple line reversal ... [   0.000s] [Task-6] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-9] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 33899). Total sessions: 1 (created=1, closed=0, expired=0)
FAIL
[   0.502s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   0.502s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.0s)
test_simple_line_reversal (test_basic_functionality.TestBasicFunctionality.test_simple_line_reversal)
Test basic line reversal functionality ... [   0.000s] [Task-16] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-19] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 35313). Total sessions: 1 (created=1, closed=0, expired=0)
[   0.501s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   0.501s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.0s)
ok

======================================================================
FAIL: test_medium_line (test_basic_functionality.TestBasicFunctionality.test_medium_line)
Test medium-sized line to ensure chunking works correctly
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_basic_functionality.py", line 141, in test_medium_line
    self.assertEqual(ack_response, f'/ack/12345/{len(medium_line)}/')
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: None != '/ack/12345/2001/'

======================================================================
FAIL: test_multiple_lines (test_basic_functionality.TestBasicFunctionality.test_multiple_lines)
Test multiple line reversal
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_basic_functionality.py", line 113, in test_multiple_lines
    self.assertEqual(ack_response, f'/ack/12345/{pos}/')
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: '/data/12345/12/dlrow\n/' != '/ack/12345/17/'
+ /ack/12345/17/
- /data/12345/12/dlrow
- /


----------------------------------------------------------------------
Ran 3 tests in 3.511s

FAILED (failures=2)
Task was destroyed but it is pending!
task: <Task pending name='Task-14' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:405> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-15' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:405> wait_for=<Future pending cb=[Task.task_wakeup()]>>

✓ Simple line reversal working correctly

    95→        """Test multiple line reversal"""
    96→        
    97→        # Connect to server
    98→        self.send_message('/connect/12345/')
    99→        response = self.receive_message()
   100→        self.assertEqual(response, '/ack/12345/0/')
   101→        
   102→        # Send multiple lines
   103→        lines = ['hello\n', 'world\n', 'test\n']
   104→        pos = 0
   105→        expected_responses = []
   106→        
   107→        for line in lines:
   108→            self.send_message(f'/data/12345/{pos}/{line}/')
   109→            pos += len(line)
   110→            
   111→            # Get ack
   112→            ack_response = self.receive_message()
   113→            self.assertEqual(ack_response, f'/ack/12345/{pos}/')
   114→            
   115→            # Get data response
   116→            data_response = self.receive_message()
   117→            self.assertIsNotNone(data_response)
   118→            expected_responses.append(line[::-1])
   119→            
   120→            # Send ack for the data response
   121→            self.send_message(f'/ack/12345/{len(line)}/')
   122→        
   123→        print("✓ Multiple line reversal working correctly")
   124→

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

The file /home/smite/dev/protohackers/7-line-reversal/test_basic_functionality.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   103→        lines = ['hello\n', 'world\n', 'test\n']
   104→        pos = 0
   105→        expected_responses = []
   106→        
   107→        for line in lines:
   108→            self.send_message(f'/data/12345/{pos}/{line}/')
   109→            pos += len(line)
   110→            
   111→            # Get responses (could be ack or data in any order)
   112→            messages = []
   113→            for _ in range(3):  # Expect up to 3 messages (ack + data response + potential ack)
   114→                response = self.receive_message(timeout=1.0)
   115→                if response:
   116→                    messages.append(response)
   117→            
   118→            # Should have gotten an ack for our data
   119→            expected_ack = f'/ack/12345/{pos}/'
   120→            ack_found = any(msg == expected_ack for msg in messages)
   121→            self.assertTrue(ack_found, f"Expected ack {expected_ack} not found in {messages}")
   122→            
   123→            # Should have gotten a data response
   124→            data_responses = [msg for msg in messages if msg.startswith('/data/12345/')]
   125→            self.assertGreater(len(data_responses), 0, "No data response received")
   126→            
   127→            # Send ack for the data responses
   128→            for data_response in data_responses:
   129→                parts = data_response.split('/')
   130→                if len(parts) >= 4:
   131→                    resp_pos = int(parts[3])
   132→                    resp_data = '/'.join(parts[4:-1])
   133→                    unescaped_data = resp_data.replace(r'\/', '/').replace(r'\\', '\\')
   134→                    ack_pos = resp_pos + len(unescaped_data)
   135→                    self.send_message(f'/ack/12345/{ack_pos}/')
   136→        
   137→        print("✓ Multiple line reversal working correctly")
   138→
   139→    def test_medium_line(self):

The file /home/smite/dev/protohackers/7-line-reversal/test_basic_functionality.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   135→                    self.send_message(f'/ack/12345/{ack_pos}/')
   136→        
   137→        print("✓ Multiple line reversal working correctly")
   138→
   139→    def test_medium_line(self):
   140→        """Test medium-sized line to ensure chunking works correctly"""
   141→        
   142→        # Connect to server
   143→        self.send_message('/connect/12345/')
   144→        response = self.receive_message()
   145→        self.assertEqual(response, '/ack/12345/0/')
   146→        
   147→        # Create a medium line (2000 characters)
   148→        medium_line = 'A' * 2000 + '\n'
   149→        
   150→        # Send the line in chunks (to respect packet size limits)
   151→        chunk_size = 800
   152→        pos = 0
   153→        while pos < len(medium_line):
   154→            chunk = medium_line[pos:pos + chunk_size]
   155→            escaped_chunk = chunk.replace('\\', r'\\').replace('/', r'\/')
   156→            
   157→            message = f'/data/12345/{pos}/{escaped_chunk}/'
   158→            # Ensure packet is under 1000 bytes
   159→            self.assertLess(len(message.encode('ascii')), 1000, 
   160→                          f"Packet size {len(message.encode('ascii'))} exceeds 1000 bytes")
   161→            
   162→            self.send_message(message)
   163→            
   164→            # Wait for ack
   165→            ack_response = self.receive_message()
   166→            expected_ack_pos = pos + len(chunk)
   167→            expected_ack = f'/ack/12345/{expected_ack_pos}/'
   168→            if ack_response != expected_ack:
   169→                # Might get data response first, keep looking
   170→                responses = [ack_response]
   171→                for _ in range(2):
   172→                    resp = self.receive_message(timeout=0.5)
   173→                    if resp:
   174→                        responses.append(resp)
   175→                
   176→                ack_found = any(resp == expected_ack for resp in responses)
   177→                self.assertTrue(ack_found, f"Expected ack {expected_ack} not found in {responses}")
   178→            
   179→            pos += len(chunk)
   180→        
   181→        # Collect all data responses
   182→        total_response_data = ""
   183→        start_time = time.time()
   184→        while time.time() - start_time < 3.0:
   185→            data_response = self.receive_message(timeout=0.5)
   186→            if data_response is None:
   187→                continue
   188→            
   189→            if data_response.startswith('/data/12345/'):
   190→                parts = data_response.split('/')
   191→                if len(parts) >= 4:
   192→                    resp_data = '/'.join(parts[4:-1])
   193→                    unescaped_data = resp_data.replace(r'\/', '/').replace(r'\\', '\\')
   194→                    total_response_data += unescaped_data
   195→                    
   196→                    # Send ack
   197→                    resp_pos = int(parts[3])
   198→                    ack_pos = resp_pos + len(unescaped_data)
   199→                    self.send_message(f'/ack/12345/{ack_pos}/')
   200→        
   201→        expected_response = medium_line[::-1]
   202→        self.assertEqual(total_response_data, expected_response)
   203→        print(f"✓ Medium line ({len(medium_line)} chars) correctly reversed and chunked")
   204→
   205→
   206→if __name__ == '__main__':
   207→    unittest.main()

✓ Multiple line reversal working correctly
test_multiple_lines (test_basic_functionality.TestBasicFunctionality.test_multiple_lines)
Test multiple line reversal ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 56668). Total sessions: 1 (created=1, closed=0, expired=0)
[   1.504s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   1.504s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 1.505s

OK

test_medium_line (test_basic_functionality.TestBasicFunctionality.test_medium_line)
Test medium-sized line to ensure chunking works correctly ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 42879). Total sessions: 1 (created=1, closed=0, expired=0)
FAIL
[   3.511s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   3.511s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=3.0s)

======================================================================
FAIL: test_medium_line (test_basic_functionality.TestBasicFunctionality.test_medium_line)
Test medium-sized line to ensure chunking works correctly
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_basic_functionality.py", line 202, in test_medium_line
    self.assertEqual(total_response_data, expected_response)
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA[1957 chars]AA\n' != '\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA[1957 chars]AAAA'
Diff is 2010 characters long. Set self.maxDiff to None to see it.

----------------------------------------------------------------------
Ran 1 test in 3.512s

FAILED (failures=1)

test_medium_line (test_basic_functionality.TestBasicFunctionality.test_medium_line)
Test medium-sized line to ensure chunking works correctly ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 56276). Total sessions: 1 (created=1, closed=0, expired=0)
FAIL
[   3.511s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   3.511s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=3.0s)
test_multiple_lines (test_basic_functionality.TestBasicFunctionality.test_multiple_lines)
Test multiple line reversal ... [   0.000s] [Task-14] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-17] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 53282). Total sessions: 1 (created=1, closed=0, expired=0)
[   1.504s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   1.504s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.0s)
ok
test_simple_line_reversal (test_basic_functionality.TestBasicFunctionality.test_simple_line_reversal)
Test basic line reversal functionality ... [   0.000s] [Task-30] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-33] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 35153). Total sessions: 1 (created=1, closed=0, expired=0)
[   0.501s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   0.501s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.0s)
ok

======================================================================
FAIL: test_medium_line (test_basic_functionality.TestBasicFunctionality.test_medium_line)
Test medium-sized line to ensure chunking works correctly
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_basic_functionality.py", line 202, in test_medium_line
    self.assertEqual(total_response_data, expected_response)
    ~~~~~~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: 'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA[1957 chars]AA\n' != '\nAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA[1957 chars]AAAA'
Diff is 2010 characters long. Set self.maxDiff to None to see it.

----------------------------------------------------------------------
Ran 3 tests in 5.520s

FAILED (failures=1)
Task was destroyed but it is pending!
task: <Task pending name='Task-27' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:405> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-28' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:405> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-29' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:405> wait_for=<Future pending cb=[Task.task_wakeup()]>>
Task was destroyed but it is pending!
task: <Task pending name='Task-35' coro=<AsyncLRCPServer.retransmit_message() done, defined at /home/smite/dev/protohackers/7-line-reversal/server.py:405> wait_for=<Future pending cb=[Task.task_wakeup()]>>

✓ Multiple line reversal working correctly
✓ Simple line reversal working correctly

-rw-r--r-- 1 tcpdump tcpdump 3271296 Aug 20 13:23 validation-1.pcap
-rw-r--r-- 1 tcpdump tcpdump 2961491 Aug 20 13:32 validation-2.pcap
-rw-r--r-- 1 tcpdump tcpdump 2829372 Aug 20 21:11 validation-3.pcap
-rw-r--r-- 1 tcpdump tcpdump 4142784 Aug 20 21:24 validation-4.pcap
-rw-r--r-- 1 tcpdump tcpdump   22489 Aug 20 21:36 validation-5.pcap
-rw-r--r-- 1 tcpdump tcpdump    6127 Aug 20 21:43 validation-6.pcap

E..6..@.......q|9.K$.....".u/data/1042987902/0/hello
E..6..@.......q|9.K$.....".u/data/1042987902/0/hello
E..6..@.@._.9.K$..q|....."../data/1042987902/0/olleh
E../..@....=..q|9.K$......../connect/248804999/
E..-..@.@._.9.K$..q|.......	/ack/248804999/0/
E.....@.......q|9.K$......../data/978643970/0/bluebell favicon good PROTOHACKERS prisoners
E..\..@.@._.9.K$..q|.....H.8/data/978643970/0/srenosirp SREKCAHOTORP doog nocivaf llebeulb
E..f..@.......q|9.K$.....R*#/data/984720514/0/the the integral for now giant giant quartz jackdaws me/
E.....@....k..q|9.K$.......|/data/248804999/0/PROTOHACKERS casino party quartz now for the casino of time is jackdaws come for of casino good time hypnotic
E../.x@.@._g9.K$..q|......../ack/248804999/180/
E....y@.@.^.9.K$..q|.......y/data/248804999/0/citonpyh emit doog onisac fo rof emoc swadkcaj si emit fo onisac eht rof won ztrauq ytrap onisac SREKCAHOTORP
E..J.z@.@._J9.K$..q|.....6.&/data/248804999/110/dia tnaig ot fo tnaig fo
E../..@.......q|9.K$......F//ack/248804999/110/
E../..@.......q|9.K$......D*/ack/248804999/135/
E..M..@.......q|9.K$.....9c./data/422174366/0/of PROTOHACKERS to the somethi/
E..U..@.......q|9.K$.....A*./data/248804999/180/hing
E../..@.@.^.9.K$..q|......../ack/248804999/472/
E.....@.@.^h9.K$..q|.......{/data/248804999/135/citonpyh emit doog onisac fo rof emoc swadkcaj si emit fo onisac eht rof won ztrauq ytrap onisac SREKCAHOTORP
E..J..@.@.^.9.K$..q|.....6.&/data/248804999/245/dia tnaig ot fo tnaig fo
E..c.	@.@.^.9.K$..q|.....O.?/data/248804999/270/gnihtemos rotaluclac won swadkcaj fo nem fo hcaep
reading from file validation-6.pcap, link-type EN10MB (Ethernet), snapshot length 262144

E../..@....>..q|9.K$......../connect/822083940/
21:43:22.321270 IP box1.protohackers.com.43486 > vps-6be738f9.vps.ovh.net.8080: UDP, length 19
E../..@....=..q|9.K$......../connect/248804999/
21:43:22.321309 IP box1.protohackers.com.43486 > vps-6be738f9.vps.ovh.net.8080: UDP, length 19
E../..@....<..q|9.K$......../connect/382593692/
--
E..-..@.@._.9.K$..q|.......	/ack/822083940/0/
21:43:22.322486 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 17
E..-..@.@._.9.K$..q|.......	/ack/248804999/0/
21:43:22.322587 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 17
E..-..@.@._.9.K$..q|.......	/ack/382593692/0/
--
/ack/984720514/55/
21:43:22.620778 IP box1.protohackers.com.43486 > vps-6be738f9.vps.ovh.net.8080: UDP, length 199
E.....@....k..q|9.K$.......|/data/248804999/0/PROTOHACKERS casino party quartz now for the casino of time is jackdaws come for of casino good time hypnotic
of giant of to giant aid
peach of men of jackdaws now calculator somet/
21:43:22.621163 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 19
E../.x@.@._g9.K$..q|......../ack/248804999/180/
21:43:22.621214 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 129
E....y@.@.^.9.K$..q|.......y/data/248804999/0/citonpyh emit doog onisac fo rof emoc swadkcaj si emit fo onisac eht rof won ztrauq ytrap onisac SREKCAHOTORP
/
21:43:22.621251 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 46
E..J.z@.@._J9.K$..q|.....6.&/data/248804999/110/dia tnaig ot fo tnaig fo
/
21:43:22.636368 IP box1.protohackers.com.43486 > vps-6be738f9.vps.ovh.net.8080: UDP, length 19
E../..@.......q|9.K$......F//ack/248804999/110/
21:43:22.636368 IP box1.protohackers.com.43486 > vps-6be738f9.vps.ovh.net.8080: UDP, length 19
E../..@.......q|9.K$......D*/ack/248804999/135/
21:43:22.720745 IP box1.protohackers.com.43486 > vps-6be738f9.vps.ovh.net.8080: UDP, length 49
E..M..@.......q|9.K$.....9c./data/422174366/0/of PROTOHACKERS to the somethi/
--
/ack/422174366/30/
21:43:22.820670 IP box1.protohackers.com.43486 > vps-6be738f9.vps.ovh.net.8080: UDP, length 313
E..U..@.......q|9.K$.....A*./data/248804999/180/hing
jackdaws prisoners casino to party of royale favicon now the
of to the favicon all favicon for is quartz love is sphinx
--
something of integral intrusion something intrusion favicon nasa peach peach hypnotic nasa come my ca/
21:43:22.821075 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 19
E../..@.@.^.9.K$..q|......../ack/248804999/472/
21:43:22.821121 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 131
E.....@.@.^h9.K$..q|.......{/data/248804999/135/citonpyh emit doog onisac fo rof emoc swadkcaj si emit fo onisac eht rof won ztrauq ytrap onisac SREKCAHOTORP
/
21:43:22.821164 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 46
E..J..@.@.^.9.K$..q|.....6.&/data/248804999/245/dia tnaig ot fo tnaig fo
/
21:43:22.821193 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 71
E..c.	@.@.^.9.K$..q|.....O.?/data/248804999/270/gnihtemos rotaluclac won swadkcaj fo nem fo hcaep
/
21:43:22.821210 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 82
E..n.
@.@.^.9.K$..q|.....Z.J/data/248804999/320/eht won nocivaf elayor fo ytrap ot onisac srenosirp swadkcaj
/
21:43:22.821231 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 80
E..l..@.@.^.9.K$..q|.....X.H/data/248804999/381/xnihps si evol ztrauq si rof nocivaf lla nocivaf eht ot fo
/
21:43:22.821245 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 56
E..T..@.@.^.9.K$..q|.....@.0/data/248804999/440/doog won dia SREKCAHOTORP llebeulb
/
21:43:22.821257 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 52
E..P..@.@.^.9.K$..q|.....<.,/data/248804999/475/emit rof swadkcaj ym gnihtemos
/
21:43:25.822699 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 131
E....I@.@.Y&9.K$..q|.......{/data/248804999/135/citonpyh emit doog onisac fo rof emoc swadkcaj si emit fo onisac eht rof won ztrauq ytrap onisac SREKCAHOTORP
/
21:43:25.822760 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 46
E..J.J@.@.Yz9.K$..q|.....6.&/data/248804999/245/dia tnaig ot fo tnaig fo
/
21:43:25.822785 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 71
E..c.K@.@.Y`9.K$..q|.....O.?/data/248804999/270/gnihtemos rotaluclac won swadkcaj fo nem fo hcaep
/
21:43:25.822800 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 82
E..n.L@.@.YT9.K$..q|.....Z.J/data/248804999/320/eht won nocivaf elayor fo ytrap ot onisac srenosirp swadkcaj
/
21:43:25.822839 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 80
E..l.M@.@.YU9.K$..q|.....X.H/data/248804999/381/xnihps si evol ztrauq si rof nocivaf lla nocivaf eht ot fo
/
21:43:25.822863 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 56
E..T.N@.@.Yl9.K$..q|.....@.0/data/248804999/440/doog won dia SREKCAHOTORP llebeulb
/
21:43:25.822885 IP vps-6be738f9.vps.ovh.net.8080 > box1.protohackers.com.43486: UDP, length 52
E..P.O@.@.Yo9.K$..q|.....<.,/data/248804999/475/emit rof swadkcaj ym gnihtemos
/
reading from file validation-6.pcap, link-type EN10MB (Ethernet), snapshot length 262144

   365→    async def process_new_complete_lines(self, session: Session, old_buffer: str):
   366→        """Process any new complete lines that weren't in the old buffer"""
   367→        self.log(f"PROCESS: Checking for new complete lines. Old buffer: {len(old_buffer)}, New buffer: {len(session.buffer)}")
   368→        
   369→        # Count complete lines in old buffer
   370→        old_lines = old_buffer.count('\n')
   371→        new_lines = session.buffer.count('\n')
   372→        
   373→        if new_lines > old_lines:
   374→            # We have new complete lines to process
   375→            self.log(f"PROCESS: Found {new_lines - old_lines} new complete lines")
   376→            
   377→            # Split buffer into lines
   378→            lines = session.buffer.split('\n')
   379→            
   380→            # Process only the new complete lines (skip the last element if it's not complete)
   381→            lines_to_process = lines[old_lines:new_lines]
   382→            
   383→            for line in lines_to_process:
   384→                reversed_line = line[::-1]
   385→                self.log(f"PROCESS: Reversing line {repr(line)} -> {repr(reversed_line)} for session {session.session_id}")
   386→                
   387→                # Send reversed line back (with newline)
   388→                response = reversed_line + '\n'
   389→                await self.send_data_chunked(session, response)
   390→        
   391→        # Update buffer to keep only the incomplete line at the end
   392→        if '\n' in session.buffer:
   393→            last_newline_pos = session.buffer.rfind('\n')
   394→            session.buffer = session.buffer[last_newline_pos + 1:]
   395→        
   396→        self.log(f"PROCESS: Buffer after processing: {repr(session.buffer)}")
   397→
   398→    async def process_new_data(self, session: Session, data: str):
   399→        """Legacy function - now redirects to process_new_complete_lines"""

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

The file /home/smite/dev/protohackers/7-line-reversal/server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   308→            await self.send_message(addr, f'/ack/{session_id}/{session.received_length}/')
   309→            session.last_ack_sent = session.received_length
   310→            self.log(f"DATA: Sent ack {session.received_length} to session {session_id}")
   311→            
   312→            # Process new data for line reversal ONLY if this is actually new data
   313→            if is_new_data:
   314→                self.log(f"DATA: Processing new data for session {session_id}")
   315→                await self.process_new_data(session, unescaped_data)
   316→            else:
   317→                self.log(f"DATA: Duplicate data for session {session_id}, not processing")
   318→        else:
   319→            # Missing data or out of order, send duplicate ack
   320→            self.log(f"DATA: Out of order data for session {session_id}, sending duplicate ack {session.last_ack_sent}")
   321→            await self.send_message(addr, f'/ack/{session_id}/{session.last_ack_sent}/')

The file /home/smite/dev/protohackers/7-line-reversal/server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   358→            
   359→            # Reset max_data_size for next chunk (in case it was reduced)
   360→            max_data_size = min(900, max_data_size * 2)  # Gradually increase back up
   361→
   362→    async def process_new_data(self, session: Session, data: str):
   363→        self.log(f"PROCESS: Adding {repr(data)} to buffer for session {session.session_id}")
   364→        session.buffer += data
   365→        
   366→        while '\n' in session.buffer:
   367→            line, session.buffer = session.buffer.split('\n', 1)
   368→            reversed_line = line[::-1]
   369→            self.log(f"PROCESS: Reversing line {repr(line)} -> {repr(reversed_line)} for session {session.session_id}")
   370→            
   371→            # Send reversed line back (with newline)
   372→            response = reversed_line + '\n'
   373→            await self.send_data_chunked(session, response)
   374→    
   375→    async def retransmit_message(self, session_id: int, pos: int, msg: str):
   376→        """Handle retransmission of a single message"""
   377→        try:

✓ Simple line reversal working correctly
/home/smite/dev/protohackers/7-line-reversal/server.py:220: SyntaxWarning: invalid escape sequence '\/'
  """Check if data contains unescaped forward slashes (which should be escaped as \/)"""
test_simple_line_reversal (test_basic_functionality.TestBasicFunctionality.test_simple_line_reversal)
Test basic line reversal functionality ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 46935). Total sessions: 1 (created=1, closed=0, expired=0)
[   0.501s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   0.501s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 0.503s

OK

✓ Multiple line reversal working correctly
test_multiple_lines (test_basic_functionality.TestBasicFunctionality.test_multiple_lines)
Test multiple line reversal ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 60514). Total sessions: 1 (created=1, closed=0, expired=0)
[   3.506s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   3.506s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=1.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 3.507s

OK

Sending long line: 50001 bytes
Received ack: /ack/12345/800/
Received ack: /ack/12345/1600/
Received ack: /ack/12345/2400/
Received ack: /ack/12345/3200/
Received ack: /ack/12345/4000/
Received ack: /ack/12345/4800/
Received ack: /ack/12345/5600/
Received ack: /ack/12345/6400/
Received ack: /ack/12345/7200/
Received ack: /ack/12345/8000/
Received ack: /ack/12345/8800/
Received ack: /ack/12345/9600/
Received ack: /ack/12345/10400/
Received ack: /ack/12345/11200/
Received ack: /ack/12345/12000/
Received ack: /ack/12345/12800/
Received ack: /ack/12345/13600/
Received ack: /ack/12345/14400/
Received ack: /ack/12345/15200/
Received ack: /ack/12345/16000/
Received ack: /ack/12345/16800/
Received ack: /ack/12345/17600/
Received ack: /ack/12345/18400/
Received ack: /ack/12345/19200/
Received ack: /ack/12345/20000/
Received ack: /ack/12345/20800/
Received ack: /ack/12345/21600/
Received ack: /ack/12345/22400/
Received ack: /ack/12345/23200/
Received ack: /ack/12345/24000/
Received ack: /ack/12345/24800/
Received ack: /ack/12345/25600/
Received ack: /ack/12345/26400/
Received ack: /ack/12345/27200/
Received ack: /ack/12345/28000/
Received ack: /ack/12345/28800/
Received ack: /ack/12345/29600/
Received ack: /ack/12345/30400/
Received ack: /ack/12345/31200/
Received ack: /ack/12345/32000/
Received ack: /ack/12345/32800/
Received ack: /ack/12345/33600/
Received ack: /ack/12345/34400/
Received ack: /ack/12345/35200/
Received ack: /ack/12345/36000/
Received ack: /ack/12345/36800/
Received ack: /ack/12345/37600/
Received ack: /ack/12345/38400/
Received ack: /ack/12345/39200/
Received ack: /ack/12345/40000/
Received ack: /ack/12345/40800/
Received ack: /ack/12345/41600/
Received ack: /ack/12345/42400/
Received ack: /ack/12345/43200/
Received ack: /ack/12345/44000/
Received ack: /ack/12345/44800/
Received ack: /ack/12345/45600/
Received ack: /ack/12345/46400/
Received ack: /ack/12345/47200/
Received ack: /ack/12345/48000/
Received ack: /ack/12345/48800/
Received ack: /ack/12345/49600/
Received ack: /ack/12345/50001/
Received data response: 915 bytes
Received data response: 917 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 520 bytes
Sent complete long line, waiting for response...
Total response data length: 50001
Expected response length: 50001
No bug detected - received appropriate amount of data
✓ Content verification: Line correctly reversed
test_very_long_line_bug (test_long_lines.TestLongLines.test_very_long_line_bug)
Test that reproduces the long line bug - infinite loop in send_data_chunked ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 44458). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.005s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 46, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.005s] [Task-3] KEEPALIVE:   Session 12345: age=0.1s, recv=36000, sent=0, pending=0
[   9.879s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   9.879s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=3.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 9.880s

OK

Testing with data: PROTOHACKERS casino party quartz now for the casino of time is jackdaws come for of casino good time hypnotic
Expected reverse: citonpyh emit doog onisac fo rof emoc swadkcaj si emit fo onisac eht rof won ztrauq ytrap onisac SREKCAHOTORP
Sending chunk at pos 0: 'PROTOHACKERS casino party quartz now for the casin'
Sending chunk at pos 50: 'o of time is jackdaws come for of casino good time'
Sending chunk at pos 100: ' hypnotic\n'
Sent complete data in 110 bytes
Received response: /data/248804999/0/citonpyh emit doog onisac fo rof emoc swadkcaj si emit fo onisac eht rof won ztrau...
Total responses received: 1
Total response data length: 110
Response data: citonpyh emit doog onisac fo rof emoc swadkcaj si emit fo onisac eht rof won ztrauq ytrap onisac SREKCAHOTORP

✅ Multi-session test passed - content correctly reversed
test_multi_session_like_validation (test_multi_session.TestMultiSession.test_multi_session_like_validation)
Test scenario similar to 1multi.test validation ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 248804999 created from ('127.0.0.1', 46046). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.006s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 5, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.006s] [Task-3] KEEPALIVE:   Session 248804999: age=4.5s, recv=110, sent=110, pending=0
[   5.509s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   5.509s] [Main] KEEPALIVE: SERVER_STOP: Session 248804999 active at shutdown (age=5.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 5.510s

OK

   362→    async def process_new_data(self, session: Session, data: str):
   363→        self.log(f"PROCESS: Adding {repr(data)} to buffer for session {session.session_id}")
   364→        session.buffer += data
   365→        
   366→        while '\n' in session.buffer:
   367→            line, session.buffer = session.buffer.split('\n', 1)
   368→            reversed_line = line[::-1]
   369→            self.log(f"PROCESS: Reversing line {repr(line)} -> {repr(reversed_line)} for session {session.session_id}")
   370→            
   371→            # Send reversed line back (with newline)
   372→            response = reversed_line + '\n'
   373→            await self.send_data_chunked(session, response)
   374→    
   375→    async def retransmit_message(self, session_id: int, pos: int, msg: str):
   376→        """Handle retransmission of a single message"""

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

   312→            # Process new data for line reversal ONLY if this is actually new data
   313→            if is_new_data:
   314→                self.log(f"DATA: Processing new data for session {session_id}")
   315→                await self.process_new_data(session, unescaped_data)
   316→            else:
   317→                self.log(f"DATA: Duplicate data for session {session_id}, not processing")
   318→        else:
   319→            # Missing data or out of order, send duplicate ack
   320→            self.log(f"DATA: Out of order data for session {session_id}, sending duplicate ack {session.last_ack_sent}")
   321→            await self.send_message(addr, f'/ack/{session_id}/{session.last_ack_sent}/')

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

test_out_of_order_with_newline_last_packet_first (test_out_of_order.TestOutOfOrder.test_out_of_order_with_newline_last_packet_first)
Test the critical scenario: last packet (with newline) arrives first ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 52509). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.005s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 4, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.006s] [Task-3] KEEPALIVE:   Session 12345: age=4.5s, recv=30, sent=0, pending=0
FAIL
[   5.509s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   5.509s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=5.0s)

======================================================================
FAIL: test_out_of_order_with_newline_last_packet_first (test_out_of_order.TestOutOfOrder.test_out_of_order_with_newline_last_packet_first)
Test the critical scenario: last packet (with newline) arrives first
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_out_of_order.py", line 142, in test_out_of_order_with_newline_last_packet_first
    self.fail("❌ BUG REPRODUCED: Server received complete out-of-order data but sent no response")
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: ❌ BUG REPRODUCED: Server received complete out-of-order data but sent no response

----------------------------------------------------------------------
Ran 1 test in 5.510s

FAILED (failures=1)

Chunk1 (pos 0): 'This is a very long line that '
Chunk2 (pos 30): 'needs to be split into multipl'
Chunk3 (pos 60): 'e packets for testing\n'
Expected reversed: 'gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT\n'

=== Sending chunk3 FIRST (with newline) ===
Response to chunk3: /ack/12345/0/

=== Sending chunk1 ===
Response to chunk1: /ack/12345/30/

=== Sending chunk2 ===
Response to chunk2: /ack/12345/30/

=== Collecting server responses ===

Total responses received: 0
Total response data: ''
Expected response: 'gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT\n'

The file /home/smite/dev/protohackers/7-line-reversal/server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   308→            await self.send_message(addr, f'/ack/{session_id}/{session.received_length}/')
   309→            session.last_ack_sent = session.received_length
   310→            self.log(f"DATA: Sent ack {session.received_length} to session {session_id}")
   311→            
   312→            # Process complete continuous data for line reversal ONLY if this is actually new data
   313→            if is_new_data:
   314→                self.log(f"DATA: Processing continuous data for session {session_id}")
   315→                await self.process_continuous_data(session, continuous_data)
   316→            else:
   317→                self.log(f"DATA: Duplicate data for session {session_id}, not processing")
   318→        else:
   319→            # Missing data or out of order, send duplicate ack
   320→            self.log(f"DATA: Out of order data for session {session_id}, sending duplicate ack {session.last_ack_sent}")
   321→            await self.send_message(addr, f'/ack/{session_id}/{session.last_ack_sent}/')

The file /home/smite/dev/protohackers/7-line-reversal/server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   358→            
   359→            # Reset max_data_size for next chunk (in case it was reduced)
   360→            max_data_size = min(900, max_data_size * 2)  # Gradually increase back up
   361→
   362→    async def process_continuous_data(self, session: Session, continuous_data: str):
   363→        """Process continuous data stream, only processing new complete lines"""
   364→        self.log(f"PROCESS: Processing continuous data for session {session.session_id}, length: {len(continuous_data)}")
   365→        
   366→        # Track how much data we've already processed to avoid reprocessing
   367→        if not hasattr(session, 'processed_data_length'):
   368→            session.processed_data_length = 0
   369→        
   370→        # Only process if we have new data beyond what we've already processed
   371→        if len(continuous_data) <= session.processed_data_length:
   372→            self.log(f"PROCESS: No new data to process (have {len(continuous_data)}, processed {session.processed_data_length})")
   373→            return
   374→        
   375→        # Get only the new data we haven't processed yet
   376→        new_data = continuous_data[session.processed_data_length:]
   377→        
   378→        # Add new data to working buffer
   379→        if not hasattr(session, 'line_buffer'):
   380→            session.line_buffer = ""
   381→        
   382→        session.line_buffer += new_data
   383→        self.log(f"PROCESS: Added {len(new_data)} new bytes to line buffer, total buffer: {len(session.line_buffer)}")
   384→        
   385→        # Process complete lines in the buffer
   386→        lines_processed = 0
   387→        while '\n' in session.line_buffer:
   388→            line, session.line_buffer = session.line_buffer.split('\n', 1)
   389→            reversed_line = line[::-1]
   390→            self.log(f"PROCESS: Reversing line {repr(line)} -> {repr(reversed_line)} for session {session.session_id}")
   391→            
   392→            # Send reversed line back (with newline)
   393→            response = reversed_line + '\n'
   394→            await self.send_data_chunked(session, response)
   395→            lines_processed += 1
   396→        
   397→        # Update how much data we've processed
   398→        session.processed_data_length = len(continuous_data) - len(session.line_buffer)
   399→        self.log(f"PROCESS: Processed {lines_processed} lines, updated processed length to {session.processed_data_length}")
   400→
   401→    async def process_new_data(self, session: Session, data: str):
   402→        """Legacy function - should not be used anymore"""
   403→        self.log(f"PROCESS: WARNING - legacy process_new_data called with {repr(data)}")
   404→        session.buffer += data
   405→        
   406→        while '\n' in session.buffer:
   407→            line, session.buffer = session.buffer.split('\n', 1)
   408→            reversed_line = line[::-1]
   409→            self.log(f"PROCESS: Reversing line {repr(line)} -> {repr(reversed_line)} for session {session.session_id}")
   410→            
   411→            # Send reversed line back (with newline)
   412→            response = reversed_line + '\n'
   413→            await self.send_data_chunked(session, response)
   414→    
   415→    async def retransmit_message(self, session_id: int, pos: int, msg: str):
   416→        """Handle retransmission of a single message"""
   417→        try:

/home/smite/dev/protohackers/7-line-reversal/server.py:220: SyntaxWarning: invalid escape sequence '\/'
  """Check if data contains unescaped forward slashes (which should be escaped as \/)"""
test_out_of_order_with_newline_last_packet_first (test_out_of_order.TestOutOfOrder.test_out_of_order_with_newline_last_packet_first)
Test the critical scenario: last packet (with newline) arrives first ... [   0.001s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 34227). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.005s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 4, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.005s] [Task-3] KEEPALIVE:   Session 12345: age=4.5s, recv=30, sent=0, pending=0
FAIL
[   5.509s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   5.509s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=5.0s)

======================================================================
FAIL: test_out_of_order_with_newline_last_packet_first (test_out_of_order.TestOutOfOrder.test_out_of_order_with_newline_last_packet_first)
Test the critical scenario: last packet (with newline) arrives first
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_out_of_order.py", line 142, in test_out_of_order_with_newline_last_packet_first
    self.fail("❌ BUG REPRODUCED: Server received complete out-of-order data but sent no response")
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: ❌ BUG REPRODUCED: Server received complete out-of-order data but sent no response

----------------------------------------------------------------------
Ran 1 test in 5.510s

FAILED (failures=1)

Chunk1 (pos 0): 'This is a very long line that '
Chunk2 (pos 30): 'needs to be split into multipl'
Chunk3 (pos 60): 'e packets for testing\n'
Expected reversed: 'gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT\n'

=== Sending chunk3 FIRST (with newline) ===
Response to chunk3: /ack/12345/0/

=== Sending chunk1 ===
Response to chunk1: /ack/12345/30/

=== Sending chunk2 ===
Response to chunk2: /ack/12345/30/

=== Collecting server responses ===

Total responses received: 0
Total response data: ''
Expected response: 'gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT\n'

The file /home/smite/dev/protohackers/7-line-reversal/test_out_of_order.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   100→        self.send_message(f'/data/12345/0/{chunk1}/')
   101→        response = self.receive_message(timeout=1.0)
   102→        print(f"Response to chunk1: {response}")
   103→        
   104→        # Send CHUNK2 last
   105→        print("\n=== Sending chunk2 ===")  
   106→        self.send_message(f'/data/12345/30/{chunk2}/')
   107→        response = self.receive_message(timeout=1.0)
   108→        print(f"Response to chunk2: {response}")
   109→        
   110→        # Let's try waiting for the final ack that indicates all data is received
   111→        final_length = len(chunk1) + len(chunk2) + len(chunk3)
   112→        print(f"\n=== Waiting for final ack /{final_length}/ ===")
   113→        for _ in range(5):
   114→            extra_response = self.receive_message(timeout=0.5)
   115→            if extra_response:
   116→                print(f"Extra response: {extra_response}")
   117→                if f'/ack/12345/{final_length}/' in extra_response:
   118→                    print("Got final ack!")
   119→                    break
   120→        
   121→        # Now collect any data responses from the server
   122→        print("\n=== Collecting server responses ===")
   123→        total_response_data = ""

test_out_of_order_with_newline_last_packet_first (test_out_of_order.TestOutOfOrder.test_out_of_order_with_newline_last_packet_first)
Test the critical scenario: last packet (with newline) arrives first ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 43244). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.004s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 4, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.004s] [Task-3] KEEPALIVE:   Session 12345: age=4.5s, recv=30, sent=0, pending=0
FAIL
[   8.013s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   8.013s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=7.5s)

======================================================================
FAIL: test_out_of_order_with_newline_last_packet_first (test_out_of_order.TestOutOfOrder.test_out_of_order_with_newline_last_packet_first)
Test the critical scenario: last packet (with newline) arrives first
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_out_of_order.py", line 153, in test_out_of_order_with_newline_last_packet_first
    self.fail("❌ BUG REPRODUCED: Server received complete out-of-order data but sent no response")
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: ❌ BUG REPRODUCED: Server received complete out-of-order data but sent no response

----------------------------------------------------------------------
Ran 1 test in 8.014s

FAILED (failures=1)

Chunk1 (pos 0): 'This is a very long line that '
Chunk2 (pos 30): 'needs to be split into multipl'
Chunk3 (pos 60): 'e packets for testing\n'
Expected reversed: 'gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT\n'

=== Sending chunk3 FIRST (with newline) ===
Response to chunk3: /ack/12345/0/

=== Sending chunk1 ===
Response to chunk1: /ack/12345/30/

=== Sending chunk2 ===
Response to chunk2: /ack/12345/30/

=== Waiting for final ack /82/ ===

=== Collecting server responses ===

Total responses received: 0
Total response data: ''
Expected response: 'gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT\n'

✓ Simple line reversal working correctly
test_simple_line_reversal (test_basic_functionality.TestBasicFunctionality.test_simple_line_reversal)
Test basic line reversal functionality ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 48553). Total sessions: 1 (created=1, closed=0, expired=0)
[   0.501s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   0.501s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 0.502s

OK

test_in_order_multi_chunk (test_in_order.TestInOrder.test_in_order_multi_chunk)
Test sending packets in order with new logic ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 36175). Total sessions: 1 (created=1, closed=0, expired=0)
FAIL
[   3.507s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   3.507s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=3.0s)

======================================================================
FAIL: test_in_order_multi_chunk (test_in_order.TestInOrder.test_in_order_multi_chunk)
Test sending packets in order with new logic
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_in_order.py", line 139, in test_in_order_multi_chunk
    self.fail(f"❌ Content mismatch!\nExpected: {repr(expected_reversed)}\nReceived: {repr(total_response_data)}")
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: ❌ Content mismatch!
Expected: 'enil tset a si sihT\n'
Received: 'enil t tset a si sihTsi sihT\n'

----------------------------------------------------------------------
Ran 1 test in 3.508s

FAILED (failures=1)

Chunk1 (pos 0): 'This is'
Chunk2 (pos 7): ' a test '
Chunk3 (pos 15): 'line\n'
Expected reversed: 'enil tset a si sihT\n'

=== Sending chunk1 ===
Response to chunk1: /ack/12345/7/

=== Sending chunk2 ===
Response to chunk2: /ack/12345/15/

=== Sending chunk3 ===
Response to chunk3: /ack/12345/20/

=== Collecting server responses ===
Received data response: /data/12345/0/enil t tset a si sihTsi sihT
/

Total responses received: 1
Total response data: 'enil t tset a si sihTsi sihT\n'
Expected response: 'enil tset a si sihT\n'

The file /home/smite/dev/protohackers/7-line-reversal/server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   308→            await self.send_message(addr, f'/ack/{session_id}/{session.received_length}/')
   309→            session.last_ack_sent = session.received_length
   310→            self.log(f"DATA: Sent ack {session.received_length} to session {session_id}")
   311→            
   312→            # Process new data for line reversal ONLY if this is actually new data
   313→            if is_new_data:
   314→                self.log(f"DATA: Processing new data for session {session_id}")
   315→                # Instead of processing just the chunk, rebuild and process from continuous data
   316→                session.buffer = continuous_data
   317→                await self.process_buffer_lines(session)
   318→            else:
   319→                self.log(f"DATA: Duplicate data for session {session_id}, not processing")
   320→        else:
   321→            # Missing data or out of order, send duplicate ack
   322→            self.log(f"DATA: Out of order data for session {session_id}, sending duplicate ack {session.last_ack_sent}")
   323→            await self.send_message(addr, f'/ack/{session_id}/{session.last_ack_sent}/')

The file /home/smite/dev/protohackers/7-line-reversal/server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   360→            
   361→            # Reset max_data_size for next chunk (in case it was reduced)
   362→            max_data_size = min(900, max_data_size * 2)  # Gradually increase back up
   363→
   364→    async def process_buffer_lines(self, session: Session):
   365→        """Process complete lines from the session buffer, avoiding duplicates"""
   366→        self.log(f"PROCESS: Processing buffer for session {session.session_id}, buffer length: {len(session.buffer)}")
   367→        
   368→        # Track how many lines we've already sent to avoid duplicates
   369→        if not hasattr(session, 'lines_sent'):
   370→            session.lines_sent = 0
   371→        
   372→        # Split buffer into lines
   373→        lines = session.buffer.split('\n')
   374→        
   375→        # The last element might be an incomplete line if it doesn't end with \n
   376→        if session.buffer.endswith('\n'):
   377→            # All lines are complete
   378→            complete_lines = lines[:-1]  # Remove empty string at end
   379→            session.buffer = ""
   380→        else:
   381→            # Last line is incomplete, keep it in buffer
   382→            complete_lines = lines[:-1]
   383→            session.buffer = lines[-1]
   384→        
   385→        # Only process lines we haven't sent yet
   386→        new_lines = complete_lines[session.lines_sent:]
   387→        
   388→        self.log(f"PROCESS: Found {len(complete_lines)} total complete lines, {len(new_lines)} new lines to process")
   389→        
   390→        for i, line in enumerate(new_lines):
   391→            reversed_line = line[::-1]
   392→            self.log(f"PROCESS: Reversing line {session.lines_sent + i + 1}: {repr(line)} -> {repr(reversed_line)}")
   393→            
   394→            # Send reversed line back (with newline)
   395→            response = reversed_line + '\n'
   396→            await self.send_data_chunked(session, response)
   397→        
   398→        # Update count of lines sent
   399→        session.lines_sent += len(new_lines)
   400→        self.log(f"PROCESS: Sent {len(new_lines)} new lines, total lines sent: {session.lines_sent}")
   401→
   402→    async def process_new_data(self, session: Session, data: str):
   403→        """Legacy function - should not be used anymore"""
   404→        self.log(f"PROCESS: WARNING - legacy process_new_data called with {repr(data)}")

Chunk1 (pos 0): 'This is'
Chunk2 (pos 7): ' a test '
Chunk3 (pos 15): 'line\n'
Expected reversed: 'enil tset a si sihT\n'

=== Sending chunk1 ===
Response to chunk1: /ack/12345/7/

=== Sending chunk2 ===
Response to chunk2: /ack/12345/15/

=== Sending chunk3 ===
Response to chunk3: /ack/12345/20/

=== Collecting server responses ===
Received data response: /data/12345/0/enil tset a si sihT
/

Total responses received: 1
Total response data: 'enil tset a si sihT\n'
Expected response: 'enil tset a si sihT\n'
✅ In-order multi-chunk test passed
/home/smite/dev/protohackers/7-line-reversal/server.py:220: SyntaxWarning: invalid escape sequence '\/'
  """Check if data contains unescaped forward slashes (which should be escaped as \/)"""
test_in_order_multi_chunk (test_in_order.TestInOrder.test_in_order_multi_chunk)
Test sending packets in order with new logic ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 37281). Total sessions: 1 (created=1, closed=0, expired=0)
[   3.506s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   3.506s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=3.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 3.507s

OK

test_out_of_order_with_newline_last_packet_first (test_out_of_order.TestOutOfOrder.test_out_of_order_with_newline_last_packet_first)
Test the critical scenario: last packet (with newline) arrives first ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.500s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 40063). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.006s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 4, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.006s] [Task-3] KEEPALIVE:   Session 12345: age=4.5s, recv=30, sent=0, pending=0
FAIL
[   8.014s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   8.014s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=7.5s)

======================================================================
FAIL: test_out_of_order_with_newline_last_packet_first (test_out_of_order.TestOutOfOrder.test_out_of_order_with_newline_last_packet_first)
Test the critical scenario: last packet (with newline) arrives first
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_out_of_order.py", line 153, in test_out_of_order_with_newline_last_packet_first
    self.fail("❌ BUG REPRODUCED: Server received complete out-of-order data but sent no response")
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: ❌ BUG REPRODUCED: Server received complete out-of-order data but sent no response

----------------------------------------------------------------------
Ran 1 test in 8.015s

FAILED (failures=1)

Chunk1 (pos 0): 'This is a very long line that '
Chunk2 (pos 30): 'needs to be split into multipl'
Chunk3 (pos 60): 'e packets for testing\n'
Expected reversed: 'gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT\n'

=== Sending chunk3 FIRST (with newline) ===
Response to chunk3: /ack/12345/0/

=== Sending chunk1 ===
Response to chunk1: /ack/12345/30/

=== Sending chunk2 ===
Response to chunk2: /ack/12345/30/

=== Waiting for final ack /82/ ===

=== Collecting server responses ===

Total responses received: 0
Total response data: ''
Expected response: 'gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT\n'

   304→        # Check if we have all data up to the current position
   305→        if pos + len(unescaped_data) == len(continuous_data):
   306→            # We have everything up to this position including current data
   307→            session.received_length = len(continuous_data)
   308→            await self.send_message(addr, f'/ack/{session_id}/{session.received_length}/')
   309→            session.last_ack_sent = session.received_length
   310→            self.log(f"DATA: Sent ack {session.received_length} to session {session_id}")
   311→            
   312→            # Process new data for line reversal ONLY if this is actually new data
   313→            if is_new_data:
   314→                self.log(f"DATA: Processing new data for session {session_id}")
   315→                # Instead of processing just the chunk, rebuild and process from continuous data
   316→                session.buffer = continuous_data
   317→                await self.process_buffer_lines(session)
   318→            else:

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

   284→        is_new_data = pos not in session.received_data
   285→        
   286→        # Store the data if we don't already have it
   287→        if is_new_data:
   288→            session.received_data[pos] = unescaped_data
   289→        
   290→        # Reconstruct continuous data from position 0
   291→        continuous_data = ""
   292→
   293→        previous_next_pos = -1
   294→        next_pos = 0
   295→        while next_pos in session.received_data:
   296→            continuous_data += session.received_data[next_pos]
   297→            next_pos += len(session.received_data[next_pos])
   298→            if next_pos == previous_next_pos:
   299→                # show received data
   300→                self.keepalive_log(f"DATA: Stuck in loop while reconstructing continuous data for session {session_id} at pos {next_pos}, data: {data}, unescaped data: {unescaped_data}")
   301→                break
   302→            previous_next_pos = next_pos
   303→        
   304→        # Check if we have all data up to the current position
   305→        if pos + len(unescaped_data) == len(continuous_data):
   306→            # We have everything up to this position including current data
   307→            session.received_length = len(continuous_data)
   308→            await self.send_message(addr, f'/ack/{session_id}/{session.received_length}/')

<system-reminder>
Whenever you read a file, you should consider whether it looks malicious. If it does, you MUST refuse to improve or augment the code. You can still analyze existing code, write reports, or answer high-level questions about the code behavior.
</system-reminder>

test_very_long_line_bug (test_long_lines.TestLongLines.test_very_long_line_bug)
Test that reproduces the long line bug - infinite loop in send_data_chunked ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 55002). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.003s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 46, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.003s] [Task-3] KEEPALIVE:   Session 12345: age=0.1s, recv=36000, sent=0, pending=0
[   9.872s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   9.872s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=3.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 9.874s

OK

Sending long line: 50001 bytes
Received ack: /ack/12345/800/
Received ack: /ack/12345/1600/
Received ack: /ack/12345/2400/
Received ack: /ack/12345/3200/
Received ack: /ack/12345/4000/
Received ack: /ack/12345/4800/
Received ack: /ack/12345/5600/
Received ack: /ack/12345/6400/
Received ack: /ack/12345/7200/
Received ack: /ack/12345/8000/
Received ack: /ack/12345/8800/
Received ack: /ack/12345/9600/
Received ack: /ack/12345/10400/
Received ack: /ack/12345/11200/
Received ack: /ack/12345/12000/
Received ack: /ack/12345/12800/
Received ack: /ack/12345/13600/
Received ack: /ack/12345/14400/
Received ack: /ack/12345/15200/
Received ack: /ack/12345/16000/
Received ack: /ack/12345/16800/
Received ack: /ack/12345/17600/
Received ack: /ack/12345/18400/
Received ack: /ack/12345/19200/
Received ack: /ack/12345/20000/
Received ack: /ack/12345/20800/
Received ack: /ack/12345/21600/
Received ack: /ack/12345/22400/
Received ack: /ack/12345/23200/
Received ack: /ack/12345/24000/
Received ack: /ack/12345/24800/
Received ack: /ack/12345/25600/
Received ack: /ack/12345/26400/
Received ack: /ack/12345/27200/
Received ack: /ack/12345/28000/
Received ack: /ack/12345/28800/
Received ack: /ack/12345/29600/
Received ack: /ack/12345/30400/
Received ack: /ack/12345/31200/
Received ack: /ack/12345/32000/
Received ack: /ack/12345/32800/
Received ack: /ack/12345/33600/
Received ack: /ack/12345/34400/
Received ack: /ack/12345/35200/
Received ack: /ack/12345/36000/
Received ack: /ack/12345/36800/
Received ack: /ack/12345/37600/
Received ack: /ack/12345/38400/
Received ack: /ack/12345/39200/
Received ack: /ack/12345/40000/
Received ack: /ack/12345/40800/
Received ack: /ack/12345/41600/
Received ack: /ack/12345/42400/
Received ack: /ack/12345/43200/
Received ack: /ack/12345/44000/
Received ack: /ack/12345/44800/
Received ack: /ack/12345/45600/
Received ack: /ack/12345/46400/
Received ack: /ack/12345/47200/
Received ack: /ack/12345/48000/
Received ack: /ack/12345/48800/
Received ack: /ack/12345/49600/
Received ack: /ack/12345/50001/
Received data response: 915 bytes
Received data response: 917 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 520 bytes
Sent complete long line, waiting for response...
Total response data length: 50001
Expected response length: 50001
No bug detected - received appropriate amount of data
✓ Content verification: Line correctly reversed

test_out_of_order_with_newline_last_packet_first (test_out_of_order.TestOutOfOrder.test_out_of_order_with_newline_last_packet_first)
Test the critical scenario: last packet (with newline) arrives first ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 56635). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.007s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 4, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.007s] [Task-3] KEEPALIVE:   Session 12345: age=4.5s, recv=30, sent=0, pending=0
FAIL
[   8.012s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   8.013s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=7.5s)

======================================================================
FAIL: test_out_of_order_with_newline_last_packet_first (test_out_of_order.TestOutOfOrder.test_out_of_order_with_newline_last_packet_first)
Test the critical scenario: last packet (with newline) arrives first
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_out_of_order.py", line 153, in test_out_of_order_with_newline_last_packet_first
    self.fail("❌ BUG REPRODUCED: Server received complete out-of-order data but sent no response")
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: ❌ BUG REPRODUCED: Server received complete out-of-order data but sent no response

----------------------------------------------------------------------
Ran 1 test in 8.014s

FAILED (failures=1)

Chunk1 (pos 0): 'This is a very long line that '
Chunk2 (pos 30): 'needs to be split into multipl'
Chunk3 (pos 60): 'e packets for testing\n'
Expected reversed: 'gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT\n'

=== Sending chunk3 FIRST (with newline) ===
Response to chunk3: /ack/12345/0/

=== Sending chunk1 ===
Response to chunk1: /ack/12345/30/

=== Sending chunk2 ===
Response to chunk2: /ack/12345/30/

=== Waiting for final ack /82/ ===

=== Collecting server responses ===

Total responses received: 0
Total response data: ''
Expected response: 'gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT\n'

test_simple_out_of_order_debug (test_out_of_order_debug.TestOutOfOrderDebug.test_simple_out_of_order_debug)
Simple 2-chunk test to debug out-of-order logic ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 46991). Total sessions: 1 (created=1, closed=0, expired=0)
FAIL
[   3.006s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   3.006s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=2.5s)

======================================================================
FAIL: test_simple_out_of_order_debug (test_out_of_order_debug.TestOutOfOrderDebug.test_simple_out_of_order_debug)
Simple 2-chunk test to debug out-of-order logic
----------------------------------------------------------------------
Traceback (most recent call last):
  File "/home/smite/dev/protohackers/7-line-reversal/test_out_of_order_debug.py", line 119, in test_simple_out_of_order_debug
    self.fail("Out-of-order packets were not properly processed")
    ~~~~~~~~~^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AssertionError: Out-of-order packets were not properly processed

----------------------------------------------------------------------
Ran 1 test in 3.007s

FAILED (failures=1)

Chunk1: 'Hello' at pos 0
Chunk2: ' World\n' at pos 5
Total expected: 'Hello World\n'

=== Sending chunk2 FIRST ===
Response to chunk2: /ack/12345/0/

=== Sending chunk1 ===
Response to chunk1: /ack/12345/0/

=== Waiting for additional responses ===
❌ No data response received - out-of-order logic failed

The file /home/smite/dev/protohackers/7-line-reversal/server.py has been updated. Here's the result of running `cat -n` on a snippet of the edited file:
   300→                self.keepalive_log(f"DATA: Stuck in loop while reconstructing continuous data for session {session_id} at pos {next_pos}, data: {data}, unescaped data: {unescaped_data}")
   301→                break
   302→            previous_next_pos = next_pos
   303→        
   304→        # Check if we have new continuous data (any extension of our continuous sequence)
   305→        if len(continuous_data) > session.received_length:
   306→            # We have new continuous data, send ack for the new length
   307→            session.received_length = len(continuous_data)
   308→            await self.send_message(addr, f'/ack/{session_id}/{session.received_length}/')
   309→            session.last_ack_sent = session.received_length
   310→            self.log(f"DATA: Sent ack {session.received_length} to session {session_id}")
   311→            
   312→            # Process new data for line reversal ONLY if this is actually new data
   313→            if is_new_data:
   314→                self.log(f"DATA: Processing new data for session {session_id}")
   315→                # Instead of processing just the chunk, rebuild and process from continuous data
   316→                session.buffer = continuous_data
   317→                await self.process_buffer_lines(session)
   318→            else:
   319→                self.log(f"DATA: Duplicate data for session {session_id}, not processing")
   320→        else:
   321→            # No new continuous data (duplicate or out of order), send duplicate ack
   322→            self.log(f"DATA: No new continuous data for session {session_id}, sending duplicate ack {session.last_ack_sent}")
   323→            await self.send_message(addr, f'/ack/{session_id}/{session.last_ack_sent}/')
   324→    
   325→    async def send_data_chunked(self, session: Session, data: str):
   326→        """Send data in chunks to avoid packets over 1000 bytes"""
   327→        max_data_size = 900  # Conservative limit to account for protocol overhead

Chunk1: 'Hello' at pos 0
Chunk2: ' World\n' at pos 5
Total expected: 'Hello World\n'

=== Sending chunk2 FIRST ===
Response to chunk2: /ack/12345/0/

=== Sending chunk1 ===
Response to chunk1: /ack/12345/12/

=== Waiting for additional responses ===
Extra response 1: /data/12345/0/dlroW olleH
/
Expected: 'dlroW olleH\\n'
Received: 'dlroW olleH\n'
✅ Out-of-order simple test PASSED
/home/smite/dev/protohackers/7-line-reversal/server.py:220: SyntaxWarning: invalid escape sequence '\/'
  """Check if data contains unescaped forward slashes (which should be escaped as \/)"""
test_simple_out_of_order_debug (test_out_of_order_debug.TestOutOfOrderDebug.test_simple_out_of_order_debug)
Simple 2-chunk test to debug out-of-order logic ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 49938). Total sessions: 1 (created=1, closed=0, expired=0)
[   0.501s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   0.502s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 0.503s

OK

Chunk1 (pos 0): 'This is a very long line that '
Chunk2 (pos 30): 'needs to be split into multipl'
Chunk3 (pos 60): 'e packets for testing\n'
Expected reversed: 'gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT\n'

=== Sending chunk3 FIRST (with newline) ===
Response to chunk3: /ack/12345/0/

=== Sending chunk1 ===
Response to chunk1: /ack/12345/30/

=== Sending chunk2 ===
Response to chunk2: /ack/12345/82/

=== Waiting for final ack /82/ ===
Extra response: /data/12345/0/gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT
/

=== Collecting server responses ===
Received data response: /data/12345/0/gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT
/

Total responses received: 1
Total response data: 'gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT\n'
Expected response: 'gnitset rof stekcap elpitlum otni tilps eb ot sdeen taht enil gnol yrev a si sihT\n'
✅ Out-of-order handling works correctly
test_out_of_order_with_newline_last_packet_first (test_out_of_order.TestOutOfOrder.test_out_of_order_with_newline_last_packet_first)
Test the critical scenario: last packet (with newline) arrives first ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 42744). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.005s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 5, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.005s] [Task-3] KEEPALIVE:   Session 12345: age=1.5s, recv=82, sent=82, pending=0
[   7.508s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   7.508s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=4.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 7.509s

OK

✓ Simple line reversal working correctly
test_simple_line_reversal (test_basic_functionality.TestBasicFunctionality.test_simple_line_reversal)
Test basic line reversal functionality ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 37561). Total sessions: 1 (created=1, closed=0, expired=0)
[   0.501s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   0.501s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=0.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 0.502s

OK

Sending long line: 50001 bytes
Received ack: /ack/12345/800/
Received ack: /ack/12345/1600/
Received ack: /ack/12345/2400/
Received ack: /ack/12345/3200/
Received ack: /ack/12345/4000/
Received ack: /ack/12345/4800/
Received ack: /ack/12345/5600/
Received ack: /ack/12345/6400/
Received ack: /ack/12345/7200/
Received ack: /ack/12345/8000/
Received ack: /ack/12345/8800/
Received ack: /ack/12345/9600/
Received ack: /ack/12345/10400/
Received ack: /ack/12345/11200/
Received ack: /ack/12345/12000/
Received ack: /ack/12345/12800/
Received ack: /ack/12345/13600/
Received ack: /ack/12345/14400/
Received ack: /ack/12345/15200/
Received ack: /ack/12345/16000/
Received ack: /ack/12345/16800/
Received ack: /ack/12345/17600/
Received ack: /ack/12345/18400/
Received ack: /ack/12345/19200/
Received ack: /ack/12345/20000/
Received ack: /ack/12345/20800/
Received ack: /ack/12345/21600/
Received ack: /ack/12345/22400/
Received ack: /ack/12345/23200/
Received ack: /ack/12345/24000/
Received ack: /ack/12345/24800/
Received ack: /ack/12345/25600/
Received ack: /ack/12345/26400/
Received ack: /ack/12345/27200/
Received ack: /ack/12345/28000/
Received ack: /ack/12345/28800/
Received ack: /ack/12345/29600/
Received ack: /ack/12345/30400/
Received ack: /ack/12345/31200/
Received ack: /ack/12345/32000/
Received ack: /ack/12345/32800/
Received ack: /ack/12345/33600/
Received ack: /ack/12345/34400/
Received ack: /ack/12345/35200/
Received ack: /ack/12345/36000/
Received ack: /ack/12345/36800/
Received ack: /ack/12345/37600/
Received ack: /ack/12345/38400/
Received ack: /ack/12345/39200/
Received ack: /ack/12345/40000/
Received ack: /ack/12345/40800/
Received ack: /ack/12345/41600/
Received ack: /ack/12345/42400/
Received ack: /ack/12345/43200/
Received ack: /ack/12345/44000/
Received ack: /ack/12345/44800/
Received ack: /ack/12345/45600/
Received ack: /ack/12345/46400/
Received ack: /ack/12345/47200/
Received ack: /ack/12345/48000/
Received ack: /ack/12345/48800/
Received ack: /ack/12345/49600/
Received ack: /ack/12345/50001/
Received data response: 915 bytes
Received data response: 917 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 918 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 919 bytes
Received data response: 520 bytes
Sent complete long line, waiting for response...
Total response data length: 50001
Expected response length: 50001
No bug detected - received appropriate amount of data
✓ Content verification: Line correctly reversed
test_very_long_line_bug (test_long_lines.TestLongLines.test_very_long_line_bug)
Test that reproduces the long line bug - infinite loop in send_data_chunked ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 12345 created from ('127.0.0.1', 56137). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.005s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 46, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.005s] [Task-3] KEEPALIVE:   Session 12345: age=0.1s, recv=36000, sent=0, pending=0
[   9.873s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   9.873s] [Main] KEEPALIVE: SERVER_STOP: Session 12345 active at shutdown (age=3.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 9.875s

OK

Testing with data: PROTOHACKERS casino party quartz now for the casino of time is jackdaws come for of casino good time hypnotic
Expected reverse: citonpyh emit doog onisac fo rof emoc swadkcaj si emit fo onisac eht rof won ztrauq ytrap onisac SREKCAHOTORP
Sending chunk at pos 0: 'PROTOHACKERS casino party quartz now for the casin'
Sending chunk at pos 50: 'o of time is jackdaws come for of casino good time'
Sending chunk at pos 100: ' hypnotic\n'
Sent complete data in 110 bytes
Received response: /data/248804999/0/citonpyh emit doog onisac fo rof emoc swadkcaj si emit fo onisac eht rof won ztrau...
Total responses received: 1
Total response data length: 110
Response data: citonpyh emit doog onisac fo rof emoc swadkcaj si emit fo onisac eht rof won ztrauq ytrap onisac SREKCAHOTORP

✅ Multi-session test passed - content correctly reversed
test_multi_session_like_validation (test_multi_session.TestMultiSession.test_multi_session_like_validation)
Test scenario similar to 1multi.test validation ... [   0.000s] [Task-1] KEEPALIVE: Server started and ready to receive packets
[   0.501s] [Task-4] KEEPALIVE: SESSION_CREATE: Session 248804999 created from ('127.0.0.1', 34662). Total sessions: 1 (created=1, closed=0, expired=0)
[   5.005s] [Task-3] KEEPALIVE: Active sessions: 1, Packets: 5, Invalid: 0, Created: 1, Closed: 0, Expired: 0
[   5.006s] [Task-3] KEEPALIVE:   Session 248804999: age=4.5s, recv=110, sent=110, pending=0
[   5.508s] [Main] KEEPALIVE: SERVER_STOP: Server stopping. Final session count: 1
[   5.508s] [Main] KEEPALIVE: SERVER_STOP: Session 248804999 active at shutdown (age=5.0s)
ok

----------------------------------------------------------------------
Ran 1 test in 5.509s

OK